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568 Cards in this Set
- Front
- Back
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What EEG waveforms are seen during dreaming?
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Beta
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Theta waves are seen in what stage of sleep?
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Stage 1
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What stage of sleep involves sleep spindles and K complexes?
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Stage 2
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Bedwetting occurs during what stage of sleep? What kind of EEG waves?
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Stage 3-4, Delta waves
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What brain structure controls eye movements in REM sleep?
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Paramedian pontine reticular formation (PPRF)
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What medicines are used for night terrors, sleepwalking, and enuresis, and what is their mechanism of action?
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Benzodiazepines - sleepwalking and night terrors
Imipramine - enuresis Both decrease stage 4 sleep |
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What test is used to diagnose narcolepsy?
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Measure CSF levels of hypocretin-1
Narcolepsy is caused by loss of hypocretin-containing neurons |
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What brain structure and neurotransmitter initiate NREM sleep?
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Ventrolateral preoptioc area (VLPO) releases GABA, which inhibits cholinergic and aminergic wake-promoting transmission
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What are the activation patterns of cholinergic and aminergic neurons during wake, NREM sleep, and REM sleep?
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Wakefulness: both activated
NREM sleep: both inactivated REM sleep: cholinergic activated, aminergic inactivated |
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Lack of the H1 histone would disrupt what process?
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chromatin supercoiling
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What are sources for the nitrogen in purines?
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Glycine
Aspartate Glutamine |
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Which amino acid is required for synthesis of both purines and pyrimidines?
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Aspartate
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What is the function of ribonucleotide reductase?
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convert ribonucleotides --> deoxyribonucleotides (for DNA)
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What mutation types usually result in a truncated protein?
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Nonsense mutation
Frameshift mutation |
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What are the roles of:
DNA polymerase I DNA polymerase II DNA polymerase III |
I - degrades RNA primer and fills gap with DNA
II - makes RNA primer III - main polymerase that elongates DNA chain |
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Which DNA polymerase has 3'-->5' exonuclease activity?
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DNA polymerase III
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Which DNA polymerase has 5'-->3' exonuclease activity?
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DNA polymerase I
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Children with extreme light sensitivity, dry skin, and risk for melanoma are deficient in what?
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Nucleotide exision repair endonuclease that can repair pyrimidine (specifically thymidine) dimers
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Patients with mutated DNA mismatch repair genes are predisposed to which cancer?
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Hereditary nonpolyposis colorectal cancer (HNPCC)
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What are the 4 steps of DNA repair, and which enzymes are involved in each step?
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1. Endonuclease cleaves damaged nucleotide
2. Exonuclease removes damaged or incorrect nucleotide 3. DNA polymerase fills gap with the corrext nucleotide 4. DNA ligase reseals the chain |
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What are the products of RNA polymerase I, II, and III?
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I - rRNA
II - mRNA III - tRNA |
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Where are snRNP's found?
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Nucleus of eukaryotic cells - responsible for splicing out introns in pre-mRNA
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What enzyme ensures that the correct amino acid is added to a polypeptide chain?
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Aminoacyl-tRNA synthetase - charges tRNA with amino acid
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What are the energy sources for mRNA translation?
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Charging tRNA - ATP --> AMP
Loading tRNA onto ribosome - GTP --> GDP Translocation - GTP --> GDP Total = 4 high energy bonds |
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In what cellular structure are cytosolic proteins synthesized?
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Free ribosomes
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In what cellular structure are secretory proteins synthesized?
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RER
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In what cellular structure are steroids synthesized?
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SER
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Children with coarse facial features, clouded corneas, and high plasma levels of lysosomal enzymes have improper functioning in what organelle?
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Golgi apparatus - I cell disease
Golgi fails to add mannose-6-phosphate to proteins that are targeted for lysosomes, resulting in extracellular secretion of lysosomal enzymes |
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Patients with Kartagener's syndrome have bronchiectasis and recurrent sinusitis. What other major defect do they have?
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Infertility - defect in dynein arm prevents ciliary motion by preventing proper linkage of microtubule peripheral 9 doublets resulting in immotile sperm
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Faulty synthesis of type III collagen predisposes to what neurologic condition?
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Berry aneurysms due to Ehler's-Danlos syndrome
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Hearing loss, blue sclera, and multiple fractures are caused by what protein abnormality?
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Osteogenesis imperfecta - abnormal type I collagen synthesis
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A person with a defective fibrillin gene is at increased risk for what pulmonary disorder?
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Emphysema due to excess elastase activity (seen in Marfan's syndrome)
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What is the enzyme associated with the rate determining step of de novo pyrimidine synthesis?
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aspartate transcarbamylase
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What is the enzyme associated with the rate determining step of de novo purine synthesis?
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glutamine-PRPP amidotransferase
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What is the enzyme associated with the rate determining step of glycolysis?
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phosphofructokinase-1 (PFK-1)
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What is the enzyme associated with the rate determining step of gluconeogenesis?
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fructose-1,6-bisphosphase (F1,6BP)
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What is the enzyme associated with the rate determining step of the TCA cycle?
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isocitrate dehydrogenase
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What is the enzyme associated with the rate determining step of glycogen synthesis?
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glycogen synthase
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What is the enzyme associated with the rate determining step of glycogenolysis?
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glycogen phosphorylase
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What is the enzyme associated with the rate determining step of the HMP shunt?
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glucose-6-phosphate dehydrogenase (G6PD)
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What is the enzyme associated with the rate determining step of fatty acid synthesis?
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Acetyl-CoA carboxylase (ACC)
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What is the enzyme associated with the rate determining step of fatty acid oxidation?
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carnitine acyltransferase 1
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What is the enzyme associated with the rate determining step of ketogenesis
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HMG-CoA synthase
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What is the enzyme associated with the rate determining step of cholesterol synthesis?
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HMG-CoA reductase
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What is the enzyme associated with the rate determining step of heme synthesis?
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ALA synthase
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What is the enzyme associated with the rate determining step of the urea cycle?
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carbamoyl phosphate synthase I
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Chronic granulomatous disease involves deficiency of what enzyme?
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NADPH oxidase
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In a fed state, what enzyme phosphorylates glucose during glycolysis in pancreatic beta cells?
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Glucokinase (induced by insulin)
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What is the fate of fructose-6-phosphate in a fed state, and what enzyme regulates this?
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Insulin dephosphorylates phosphofructokinase-2 (PFK-2) to promote synthesis of fructose-2,6-bisphosphate.
F2,6BP then activates PFK-1, which catalyzes the transformation of F6P to F1,6BP, promoting the use of F6P for glycolysis rather than gluconeogenesis |
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Glycolytic enzyme deficiency has what impact on RBCs?
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hemolytic anemia because RBCs can only metabolize glucose anaerobically via glycolysis
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What causes lactic acidosis in alcoholics?
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Vitamin B1 deficiency causes deficiency in pyruvate dehydrogenase complex function. Instead of forming acetyl-CoA, pyruvate forms lactate.
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What are the 4 major metabolic pathways that pyruvate can participate in?
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Pyruvate --> alanine (carries amino group to liver from muscle)
Pyruvate --> oxaloacetate (can enter TCA or be used for gluconeogenesis) Pyruvate --> Acetyl-CoA (can enter TCA cycle or FA synthesis) Pyruvate --> Lactate (end of anaerobic glycolysis pathway) |
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What cofactors are required for the alpha-ketoglutarate dehydrogenase complex?
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B1, B2, B3, B5, lipoic acid
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At what point in the TCA cycle is GTP synthesized?
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Succinyl-CoA --> Succinate (yields GTP + CoA)
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What reactions yield NADH in the TCA cycle?
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isocitrate --> alpha-KG
alpha-KG --> succinyl-CoA malate --> oxaloacetate |
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Where in the body can gluconeogenesis occur?
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liver, kidney, intestinal epithelium
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What is the pathway for odd-chain FAs to undergo gluconeogenesis?
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Odd-chain FA --> propionyl-CoA --> methylmalonyl-CoA --> succinyl-CoA --> [TCA] --> Oxaloacetate --> phosphoenolpyruvate (PEP) --> --> --> Glucose
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G6P can either directly convert to F6P or go through an indirect pathway. What is the indirect pathway?
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HMP shunt (pentose phosphate shunt):
G6P --G6PD--> 6-phosphogluconolactone (6PG) --> --> --> ribulose-5-phosphate --transketolase--> F6P |
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What is the purpose of the HMP shunt?
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To synthesize NADPH for FA and steroid biosynthesis and for the glutathione reductase reaction inside RBCs.
Also to synthesize ribose-5-phosphate for nucleotide synthesis |
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Heinz bodies and bite cells are indicative of what enzyme deficiency?
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G6PD - NADPH is not available to couple with reduction of glutathione in RBCs. Reduced glutathione is necessary to detoxify free radicals and peroxides in RBCs. Hemolytic anemia, with Heinz bodies due to Hb precipitates in RBCs, and bite cells result from phagocytic removal of Heinz bodies by macrophages.
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G6PD deficiency is protective for what infectious disease?
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Malaria
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Someone with a deficiency of aldolase B is likely to have accumulation of what?
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Fructose-1-phosphate
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What kind of treatment should hypoglycemic patients with jaundice, cirrhosis, and vomiting receive?
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Decreased intake of fructose and sucrose
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Fructose in the blood and urine is associated with what enzyme deficiency? What is the pathology?
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Fructokinase, benign and asymptomatic condition
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Metabolism of fructose yields what product that then enters glycolysis?
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Glyceraldehyde-3-phosphate
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Excess accumulation of galactose-1-phosphate is associated with deficiency of what enzyme?
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Galactose-1-phosphate uridyl transferase
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Metabolism of galactose yields what product that can either participate in glycolysis or gluconeogenesis?
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Glucose-1-phosphate
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The toxic metabolite galactitol can accumulate in what enzyme deficiency?
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Galactokinase
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Osmotic diarrhea that is caused by loss of a brush border cell enzyme is treated by what?
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Lactase deficiency - avoid milk and other lactose products or add lactase pills to diet
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Infants born with a musty body odor are likely to require what dietary supplement?
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Tyrosine due to PKU
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Where do the nitrogens in urea come from?
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1 from NH4+ and 1 from aspartate
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Where does the rate-limiting step of the urea cycle occur in the cell?
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mitochondria of hepatocytes
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What reaction forms urea?
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arginine --arginase--> ornithine (urea synthesized as a byproduct)
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Where in the cell is urea synthesized?
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cytoplasm of hepatocytes
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What product synthesized by the urea cycle can be used in the TCA cycle?
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fumarate (formed in reaction arginosuccinate --arginosuccinase--> arginine)
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A patient's urine sample turns black after standing out for a while. What enzyme is deficient?
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homogentisic acid oxidase (part of tyrosine degradation pathway)
Alkaptonuria |
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A patient with symptoms of mental retardation, osteoporosis, kyphosis, and atherosclerosis is likely to need what in their diet?
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Cystein due to homocystinuria
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Homocystinuria can cause excess accumulation of what product?
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homocystein
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In cystinuria, renal tubular amino acid transporters is defective for which amino acids?
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Cysteine
Ornithine Lysine Arginine |
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Cystine kidney stones caused by excess cystine in the urine is caused by a defect in what part of the renal tubular system?
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proximal convoluted tubule
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High levels of isoleucine, leucine, and valine in the blood are indicative of what disorder?
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Maple syrup urine disease
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In maple syrup urine disease, what enzyme is deficient?
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alpha-ketoacid dehydrogenase
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SCID is caused by what enzyme deficiency?
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adenosine deaminase
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A patient with mental retardation demonstrates self mutilation and aggressive behavior. What enzyme is deficient and what substance is likely to be produced in excess?
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HGPRT deficiency
Uric acid excess can result in gout or hyperuricemia (Lesch-Nyhan syndrome) |
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What is the main metabolic fuel source for the duration of a marathon?
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glycogen and FFA oxidation
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After a few days of starvation, what is the muscle's fuel source?
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FFA, ketone bodies
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What is the main stimulus for synthesis of insulin by pancreatic beta cells?
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ATP from glucose metabolism acts on K+ channels to depolarize cells
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Where is the GLUT1 receptor found? Does it rely in insulin?
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Brain and RBCs, does not require insulin for glucose uptake
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What kind of bonds are seen in glycogen?
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alpha (1,6) bonds in branches and alpha (1,4) bonds in linear linkages
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What enzymes break the bonds in glycogen during glycogenolysis?
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glycogen phosphorylase hydrolyzes alpha (1,4) linkages and debranching enzyme hydrolyzes alpha (1,6) branches to create a linear chain
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A patient with severe fasting hypoglycemia is also found to have very high levels of glycogen in her liver and high blood lactate. What disease does she have and what enzyme is deficient?
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Von Gierke's disease, glucose-6-phosphatase
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Lysosomal degradation of glycogen involves what enzyme?
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lysosomal alpha-1,4-glucosidase
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Deficient glycogen degradation in lysosomes by alpha-1,4-glucosidase is caused by what disease and involves what serious sequelae?
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Pompe's disease, cardiomegaly
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Debranching enzyme deficiency is seen in what glycogen storage disease?
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Cori's disease
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McArdle's disease involves painful muscle cramps and myoglobinuria with strenuous exercise due to what enzyme deficiency?
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Glycogen phosphorylase
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Accumulation of ceramide trihexoside is associated with what enzyme deficiency?
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alpha-galactosidase A (Fabry's disease)
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Patients with Gaucher's disease present with hepatosplenomegaly, aseptic necrosis of the femur, and bone crises. What enzyme is deficient and what substrate accumulates?
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beta-glucocerebrosidase, glucocerebroside
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Two lysosomal storage diseases involve progressive neurodegeneration and a cherry-red spot. What is the disease, enzyme deficiency, and accumulated substrate if the disease presents with hepatosplenomegaly? If it does not?
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hepatosplenomegaly - Niemann-Pick disease, sphingomyelinase, sphingomyelin
no hepatosplenomegaly - Tay-Sachs disease, hexosaminidase A, GM2 ganglioside |
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Galactocerebrosidase deficiency involves what findings?
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Krabbe's disease - accumulation of galactocerebrosidase, peripheral neuropathy, developmental delay, optic atrophy, globoid cells
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Arylsulfatase A deficiency involves what substrate accumulation?
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cerebroside sulfate
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Two lysosomal storage diseases involve accumulation of heparan sulfate and dermatan sulfate. What is the disease and enzyme deficiency if the disease involves corneal clouding? If it does not?
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Corneal clouding - Hurler's syndrome, alpha-L-iduronidase
No corneal clouding - Hunter's syndrome, iduronidate sulfatase |
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What shuttle is involved for acetyl-CoA transport in FA synthesis and acyl-CoA transport in FA degradation?
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Synthesis - citrate shuttle
Degradation - carnitine shuttle |
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What is the major product of FA degradation?
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Acetyl-CoA
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What is the role of the enzyme LCAT?
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lecithin-cholesterol acyltransferase esterifies 2/3 of plasma cholesterol
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HDL transports cholesterol from where to where?
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centripetal transport from periphery to liver
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Autosomal dominant familial hypercholesterolemia is caused by deficiency in what?
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LDL receptors
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Porphyrias are caused by accumulations of what?
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Heme synthesis intermediates
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What are the symptoms of porphyrias?
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5Ps: Painful abdomen, Pink urine, Polyneuropathy, Psychological disturbances, Precipitated by drugs
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Tea-colored urine is caused by what enzyme deficiency?
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Uroporphyrinogen decarboxylase (Porphyria cutania tarda)
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What can be given to treat cyanide poisoning?
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Nitrites - they oxidize hemoglobin to methemoglobin (contains ferric, Fe3+ instead of ferrous, Fe2+), and methemoglobin has a higher affinity for cyanide
Thiosulfate can then be given to bind the cyanide to form thiocyanate, which is renally excreted |
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Carbon monoxide poisoning is associated with what form of hemoglobin?
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carboxyhemoglobin
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A 25 year old with high cholesterol and tendon xanthomas most likely has what disease?
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Familial hypercholesterolemia
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Patients with Marfan's syndrome have what mutation?
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fibrillin gene mutation
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An autosomal dominant mutation in the long arm of chr. 17 involves findings of cafe-au-lait spots, neural tumors, Lisch nodules, and skeletal disorders. What is the gene abnormality?
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abnormal neurofibromin tumor suppressor gene in Neurofibromatosis type I (von Recklinghausen's disease)
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Bilateral acoustic neuroma and juvenile cataracts are seen in mutations of the NF2 gene on which chromosome?
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Chr. 22 (Neurofibromatosis type II)
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What disease involves facial lesions, hypopigmented skin, cortical and retinal hamartomas, seizures, mental retardation, renal cysts and angiomyolipomas, cardiac rhabdomyomas, and astrocytomas?
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Tuberous sclerosis
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Deletion of the VHL gene on chr. 3 is associated with what neoplasms?
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hemangioblastomas of the retina, cerebellum, or medulla; multople bilateral renal cell carcinomas
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What chromosome is abnormal in Huntington's disease?
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CAG repeats in chr. 4
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What parental factor increases risk of passing on the autosomal dominant gene for achondroplasia?
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increased paternal age
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Heterozygotes for the CFTR gene defect do not have cystic fibrosis, but are at increased risk for what disease?
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pancreatitis
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Hypertrophic calves and increased CPK are seen in what x-linked disease?
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Duchenne's muscular dystrophy
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What chromosomal defect causes Fragile X syndrome?
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abnormal methylation and expression of FMRI1 gene due to CGG repeats, may result in chromosomal breakage
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Cleft lip is seen in what autosomal trisomy?
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Trisomy 13
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Prominent occiput with micrognathia (small jaw) is seen in what autosomal trisomy?
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Trisomy 18
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Patient's with Down syndrome often have what congenital heart defect?
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septum primum ASD
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What chromosomal abnormality is seen in Cri-du-chat syndrome?
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deletion of short arm of chr. 5
46,XX or XY, 5p- |
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What week of development does the heart begin to beat?
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Week 4
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Organogenesis occurs during which weeks of development?
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Weeks 3-8
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What is the embryologic derivative of the lens of the eye?
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surface ectoderm
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What is the embryologic derivative of the adenohypophysis?
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surface ectoderm
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What is the embryologic derivative of the neurohypophysis?
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neuroectoderm
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What is the embryologic derivative of astrocytes?
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neuroectoderm
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What is the embryologic derivative of CNS neurons?
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neuroectoderm
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What is the embryologic derivative of the pineal gland
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neuroectoderm
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What is the embryologic derivative of the ANS?
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neural crest
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What is the embryologic derivative of melanocytes?
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neural crest
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What is the embryologic derivative of chromaffin and enterochromaffin cells?
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neural crest
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What is the embryologic derivative of schwann cells?
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neural crest
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What is the embryologic derivative of the skull bones?
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neural crest
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What is the embryologic derivative of gut epithelium?
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endoderm
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What is the embryologic derivative of the liver?
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endoderm
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What is the embryologic derivative of the lungs?
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endoderm
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What is the embryologic derivative of the thymus?
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endoderm
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What is the embryologic derivative of the thyroid and parathyroid glands?
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endoderm
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What is the embryologic derivative of the dura mater?
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mesoderm
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What is the embryologic derivative of the pia and arachnoid mater?
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neural crest
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What is the embryologic derivative of lymphatics?
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mesoderm
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What is the embryologic derivative of the spleen?
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mesoderm
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What structure signals what structure to form the neuroectoderm?
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notochord induced the ectoderm to form neuroectoderm
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ACE inhibitors used during weeks 3-8 of pregnancy can have what effect on the fetus?
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renal damage
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What teratogen can cause congenital goiter in the fetus?
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iodide
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The embryonic bulbus cordis gives rise to what structure?
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smooth parts of left and right ventricle
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The coronary sinus is derived from which embryonic structure?
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left horn of the sinus venosus
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The right horn of the embryonic sinus venosus gives rise to what structure?
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smooth part of the right atrium
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The ascending aorta is derived from which embryonic structure?
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truncus arteriosus
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Faulty development of the interventricular spiral septum can cause what congenital heart abnormalities?
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tetralogy of fallot
persistent truncus arteriousus transposition of the great arteries |
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What structure forms the valve of the foramen ovale?
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septum primum
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What are the important shunts in fetal circulation?
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ductus venosus
ductus arteriosus foramen ovale |
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What is the derivative of the first aortic arch?
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maxillary sinus
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What is the derivative of the third aortic arch?
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common carotid artery and proximal internal carotid artery
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The ductus arteriosus is derived from which aortic arch?
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6th
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What branchial arches are the ear bones derived from?
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malleus and incus - arch 1
stapes - arch 2 |
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What is the major function of the muscles derived from branchial arch 1?
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muscles of mastication - temporalis, masseter, lateral and medial pterygoids
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Cranial nerve IX is derived from which branchial arch?
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arch 3
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Where are the muscles of facial expression derived from?
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branchial arch 2
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What cranial nerves are derived from branchial arch 1?
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V2 and V3
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Cranial nerve VII is derived from which branchial arch?
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arch 2
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What are the major derivatives of branchial arch 3?
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greater horn of hyoid, stylopharyngeus muscle, CN IX
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Where is the tongue and its neural inputs derived from?
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anterior 2/3 - branchial arch 1, sensation via CN V3, taste via CN VII
posterior 1/3 - branchial arches 4-6, taste via CN IX and X motor innervation via CN XII |
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What intrinsic laryngeal muscle is NOT derived from branchial arch 6?
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cricothyroid (derived from branchial arch 4)
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What cranial nerve is derived from branchial arch 4 and from branchial arch 6?
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4 - superior laryngeal branch of CN X
6 - recurrent laryneal branch of CN X |
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What branchial arch is the thyroid derived from?
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arches 4-6
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What structure is the external auditory meatus derived from?
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branchial cleft 1
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What are the derivatives of branchial pouch 1?
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middle ear cavity, eustachian tube, mastoid air cells
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What does the ventral portion of the 3rd branchial pouch form?
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thymus
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What structures give rise to the parathyroids?
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dorsal wings of 3rd branchial pouch - inferior parathyroids
dorsal wings of 4th branchial pouch - superior parathyroids |
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What syndrome results from aberrant development of the 3rd and 4th branchial pouches?
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DiGeorge syndrome - T cell deficiency due to thymic aplasia and hypocalcemia due to failed parathyroid development
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What nerves innervate the muscles associated with the ear bones?
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malleus and incus - tensor tympani - CN V3
Stapes - stapedius - CN VII |
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Failed fusion of the lateral palatine processes, nasal septum, and/or the median palatine process?
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cleft palate
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What developmental abnormality results in cleft lip?
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failed fusion of maxillary and medial nasal processes
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An infant who is intolerant to oral feeding and has bilious vomiting most likely has what congenital abnormality?
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annular pancreas - ventral pancreatic bud encircles duodenum causing duodenal narrowing
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An infant who has a distended abdomen and has not passed meconium after a few weeks likely has abnormal migration of what embryological cell type?
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neural crest cells - Hirschsprung disease
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Meckel's diverticulum is due a persistent remnant of what structure?
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vitelline duct
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During week 11 of development, the midgut rotates how many degrees around which structure?
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270 degrees around the superior mesenteric artery
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Urine drainage from the umbilicus of an infant is due to what congenital abnormality?
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urachal fistula/cyst due to persistant allantois remnant
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A horseshoe kidney becomes entrapped by which structure as it migrates?
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inferior mesenteric artery
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What ultrasound finding can be caused by Potter's syndrome?
|
oligohydramnos due to bilateral renal agenesis
|
|
|
What is the female structure analogous to the male prostate gland?
|
urethral and paraurethral glands of Skene
|
|
|
What male structure is analogous to the female vestibular bulbs?
|
Corpus spongiosum
|
|
|
The bulbourethral glands of Cowper are found in what sex, and what is its analogous structure in the opposite sex?
|
bulbourethral glands of Cowper in males analogous to greater vestibular glands of Bartholin in females
|
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|
Congenital megacolon is associated with failed migration of what cells?
|
neural crest
|
|
|
Spina bifida is a defect in what embryologic structure?
|
neural tube
|
|
|
The common myeloid progenitor gives rise to what cells?
|
thrombocytes, erythrocytes, mast cells, basophils, neutrophils, eosinophils, macrophages, myeloid dendritic cells
|
|
|
What is cell precursor for thrombocytes?
|
megakaryocytes
|
|
|
What cells are granulocytes?
|
basophils, eosinophils, neutrophils
|
|
|
What hematologic cell has a bilobate nucleus and contains heparin in its granules?
|
basophil
|
|
|
Hypersegmented polymorphonuclear leukocytes are seen in what deficiency?
|
Vitamin B12/folate deficiency in pernicious anemia
|
|
|
Plasma cells are derived from what cell type?
|
B cells
|
|
|
What does thrombin activate in the coagulation cascade, and what pathway is it part of?
|
fibrin, common pathway
|
|
|
What is the role of the product activated by thrombomodulin in the coagulation cascade?
|
thrombomodulin activates protein C, using protein S as a cofactor
protein C inactivates factor VIIIa in the intrinsic pathway and factor Va in the common pathway |
|
|
PTT does NOT measure action of what coagulation factors?
|
VII and XIII
|
|
|
What is the role of factor XIIIa in the coagulation cascade?
|
cross-link fibrin clots
|
|
|
Antithrombin III inactivates what coagulation factors?
|
IXa, Xa, XIa
|
|
|
What is the role of factor VIIIa in the coagulation cascade?
|
Cofactor for activation of factor X by factor IXa in the intrinsic pathway
|
|
|
PT measures the action of what coagulation pathway?
|
extrinsic - factors II, V, VII, X
|
|
|
What influence does tPA have in the coagulation cascade?
|
tPA activates plasminogen to form plasmin, which breaks cross-links between fibrin clots to stop coagulation
|
|
|
What are the steps in the part of the coagulation pathway measured by PTT?
|
XII --> XIIa, activates XI --> XIa, activates IX --> IXa, activates X --> Xa with VIIIa cofactor
|
|
|
What are the steps in the coagulation pathway that is measured by PT?
|
VII --> VIIa with tissue factor cofactor, activates X --> Xa
|
|
|
What are the steps in the common coagulation pathway?
|
Xa activates prothrombin (II) --> thrombin (IIa) with Va cofactor, thrombin activates fibrinogen (I) --> fibrin (Ia), factor XIIIa cross-links fibrin clots
|
|
|
What thrombophilic condition involves disabled protein C function?
|
Factor V Leiden mutation
|
|
|
A patient with CC: fatigue has low Hb and MCV. What is the likely diagnosis?
|
Iron-deficiency anemia
|
|
|
What is the blood type of a patient who has A antibody in their plasma?
|
B
|
|
|
Gastritis and neurological problems are seen in what anemia?
|
pernicious anemia - failure to produce intrinsic factor
|
|
|
What activates antithrombin III?
|
heparin
|
|
|
Lead poisoning can cause what kind of anemia?
|
microcytic, hypochromic
|
|
|
What is the mechanism for anemia in iron deficiency?
|
impaired synthesis of heme
|
|
|
A patient with recent history of mononucleosis develops fatigue and purpura, with marked hypocellularity on bone marrow biopsy. What does he have, and what will lab reports show?
|
Aplastic anemia - pancytopenia
|
|
|
Decreased serum iron and decreased TIBC are found in what type of anemia?
|
Anemia of chronic disease
|
|
|
Chronic autoimmune hemolytic anemia with IgG antibodies are associated with what neoplastic disorder?
|
Warm agglutinin is associated with CLL
|
|
|
A patient with a recent history of EBV infection has acute onset of Coomb's positive anemia. What antibody is involved?
|
IgM - Cold agglutinin
|
|
|
What is the defective protein in hereditary spherocytosis?
|
ankyrin or spectrin
|
|
|
Patients with a genotype HbSC have a mutation in what hemoglobin chain?
|
beta chain - milder form of sickle cell disease
|
|
|
Hydrops fetalis is caused by what disorder?
|
Hb Barts alpha-thalassemia
|
|
|
Protein rich fluid travels through the glomerulus to what structure?
|
Efferent arteriole
|
|
|
A woman is injected with 1g mannitol. Plasma concentration of mannitol after equilibration is 0.08g/L, and during the equilibration, 20% of the injected mannitol was excreted in the urine. Calculate the ECF. What information would be needed to calculate the interstitial fluid volume?
|
Amount of mannitol after equilibrium = 1.0g - 0.20g = 0.80g
Concentration = Amount/Volume 0.08 = 0.80/V V = 0.80/0.08 V = 10L To calculate interstitial fluid volume, we would need to know the plasma volume (ECF volume - plasma volume = interstitial fluid volume) |
|
|
Intracellular fluid is what percent of total body weight?
|
40%
|
|
|
Extracellular fluid is what percent of total body weight?
|
20%
|
|
|
Plasma volume is what percent of total body water?
|
1/4 x 1/3 = 1/12
plasma volume = 1/4 of ECF fluid ECF fluid = 1/3 of total body water |
|
|
Radiolabeled albumin can be used to measure what volume?
|
plasma volume
|
|
|
Inulin can be used to measure what volume?
|
ECF
|
|
|
A woman with is infected with C. difficile. Describe the changes that would occur in her extracellular and intracellular fluid volumes.
|
Diarrhea --> isotonic loss of volume
ECF volume will decrease ICF volume will stay the same (b/c no change in osmolarity) |
|
|
After eating a salty meal, how does the body's extracellular and intracellular fluid volume and osmolarity change?
|
Salty meal --> hyperosmotic increase in volume
ECF osmolarity increases because of hyperosmotic volume increase Water will shift from ICF to ECF until they are at equal osmolarity, so ICF volume will decrease Net increase in ECF volume and osmolarity, and ICF volume |
|
|
What is the formula for calculating renal clearance of a substance?
|
C = UV/P
U = urine concentration V = urine flow rate P = plasma concentration |
|
|
How can renal plasma flow be measured?
|
Use PAH
C = UV/P |
|
|
Plasma concentration of substance X = 140mEq/L, and urine concentration = 700mEq/L with a flow rate of 1mL/min. If the GFR = 120mL/min, is substance X filtered, secreted, or reabsorbed?
|
Cx = 700 x 1 / 140 = 5mL/min
Cx < GFR, so net reabsorption |
|
|
What structure prevents albumin from glomerular filtration?
|
fenestrated capillary endothelium - size barrier
based membrane with heparin sulfate - negative charge barrier |
|
|
How will constriction of the ureters change GFR?
|
ureter constriction - increased Pbs --> decreased GFR
|
|
|
What percent of the fluid entering the renal afferent arteriole will exit the renal efferent arteriole?
|
80% (filtration fraction = 20%
|
|
|
ACE inhibitors will have what effect on GFR?
|
Angiotensin II constricts efferent arterioles, so ACE inhibitors will dilate efferent arterioles, resulting in decreased GFR
|
|
|
A ureteral stone will have what effect on FF?
|
FF will decrease because GFR decreases and RPF does not change
FF = GFR/RPF |
|
|
Why does glucosuria occur in patients with uncontrolled DM?
|
glucose is normally completely reabsorbed at the proximal tubule, but after plasma threshold of 200mg/dL, glucose cannot be completely reabsorbed and some is excreted. At, 350mg/dL, the glucose transporter is saturated, so any increase in plasma glucose will be excreted
|
|
|
What substances are reabsorbed in the thin ascending loop of henle?
|
water, through aquaporins, causing concentration of urine
|
|
|
Where in the nephron are ionized drugs excreted?
|
proximal convoluted tubule
|
|
|
Where in the nephron do carbonic anhydrase inhibitors exert their action?
|
proximal convoluted tubule
|
|
|
Reabsorption of Na+ in the thick ascending limb required what important cotransporter?
|
Na/K/2Cl pump
|
|
|
Increased PTH levels will activate what second messenger system in the distal convoluted tubule?
|
adenylate cyclase, resulting in increased Ca reabsorption
|
|
|
Increased PTH levels will inhibit what transporter in the proximal tubule?
|
Na+/Phosphate cotransporter, resulting in decreased phosphate reabsorption, phosphaturia, and increased urinary cAMP
|
|
|
Secretion of K+ occurs in what part of the nephron?
|
principal cells of the collected tubule
|
|
|
Angiotensin II increases GFR by what mechanism?
|
efferent arteriole constriction
|
|
|
GFR increases to compensate for high pressure measured in the atria. What substance mediates this?
|
ANP - atrial natriuretic factor
|
|
|
Low blood volume in the distal convoluted tubule will increase GFR via what mechanism?
|
macula densa of DCT signals JGA to release renin, activating the RAA complex to increase the GFR
|
|
|
In cases of hypoxia, the renal peritubular capillary will release what substance?
|
endothelial cells secrete erythropoietin
|
|
|
NSAIDS are associated with risk of acute renal failure with high GFR due to what factor?
|
inhibit renal production of prostaglandins, which vasodilate the afferent arterioles to increase GFR
|
|
|
Where is the site of action of the pituitary hormone that increases urine concentration?
|
ADH acts at the collecting tubule to increase aquaporin channels in the principal cells and thus increase water reabsorption
|
|
|
In nephrogenic diabetes insipidus, which direction will water flow in the collecting duct?
|
none - nephrogenic diabetes insipidus is a result of ineffective ADH, and without ADH, the collecting duct is impermeable to water
|
|
|
Hyperosmotic urine is produced in cases of water deprivation or what disease?
|
SIADH
|
|
|
The primary disturbance in acidosis resulting in Kussmaul breathing is what?
|
low bicarbonate in metabolic acidosis
|
|
|
Excessive vomiting results in hypoventilation because of what acid/base disorder?
|
metabolic alkalosis due to loss of H+ in gastric acid
|
|
|
A patient with acidosis secondary to opiate abuse will show what type of renal compensation?
|
increase H+ excretion
increase bicarb reabsorption respiratory acidosis due to depressed breathing |
|
|
What conditions are associated with metabolic acidosis with high anion gap?
|
MUDPILES:
methanol uremia diabetic ketoacidosis paraldehyde or phenformin iron tablets or INH lactic acidosis ethylene glycol salicylates |
|
|
What are three mechanisms of renal tubular acidosis?
|
Type 1 - defect in H+ pump
Type 2 - renal loss of bicarb Type 4 - hypoaldosteronism --> hyperkalemia --> inhibition of ammonia excretion |
|
|
Granular casts seen in acute tubular necrosis left untreated will cause what outcome?
|
death due to acute renal failure, usually in oliguric phase of acute tubular necrosis
|
|
|
Hematuria, facial edema, and enlarged hypercellular glomerulus with increased neutrophils will demonstrate what pattern on electron microscopy?
|
subepithelial humps - acute post-streptococcal glomerulonephritis
|
|
|
How can membranoproliferative glomerulonephritis and membranous glomerulonephritis be differentiated?
|
membranoproliferative - nephritis syndrome - hematuria
membranous - nephrotic syndrome - proteinuria |
|
|
A patient with hematuria and hypertension demonstrates many crescents on light microscopic exam of the glomerulus. What is the likely outcome?
|
rapid progression to renal failure due to rapidly progressive glomerulonephritis
|
|
|
What is a characteristic microscopic finding in Alport's syndrome?
|
split basement membrane of the glomerulus
|
|
|
A patient presents with hemoptysis and hematuria. What type of immune reaction is this?
|
type II hypersensitivity due to goodpasture's syndrome (anti-basement membrane antibodies)
|
|
|
In Berger's disease, what type of deposits will be present in the kidney mesangium?
|
IgA (IgA nephropathy)
|
|
|
A patient with lupus presents with low serum albumin. What is the diagnosis?
|
SLE associated nephrotic syndrome
|
|
|
The most common cause of childhood nephrotic syndrome should be treated with what class of drugs?
|
steroids - minimal change disease
|
|
|
Proteinuria associated with hyaline deposits in the glomerulus is caused by what disease?
|
focal segmental glomerular sclerosis
|
|
|
Amyloidosis associated nephropathy is associated with what bacterial infection?
|
mycobacterium tuberculosis
|
|
|
Linear pattern immunofluorescence is seen in what nephritic disease?
|
Goodpasture's syndrome
|
|
|
A patient with primary parathyroidism develops a kidney stone. What type of kidney stone does the patient have?
|
Calcium due to hypercalcemia and hypercalciuria
|
|
|
An alcoholic patient with a recent pneumonia develops a kidney stone. What type of stone does the patient have?
|
Struvite - caused by infection with urease positive bacteria, in this case Klebsiella
|
|
|
A leukemic patient develops a kidney stone. What will the x-ray show?
|
nothing - uric acid stones are not visible on x-ray or CT
|
|
|
Why is it important to differentiate struvite from cystine kidney stones?
|
cystine stones are treated by alkalinization of urine, whereas struvite stones are made worse by alkaluria
|
|
|
How does renal cell carcinoma typically metastasize?
|
invades IVC --> hematogenous spread
|
|
|
A 2 year old child has a huge palpable flank mass. What chromosome is likely abnormal?
|
Chr. 11 - Wilms tumor due to deletion of WT1 gene
|
|
|
Painless hematuria suggests cancer of what cell type?
|
transitional cell - bladder
|
|
|
White cell casts in the urine involves inflammation in what parts of the kidney?
|
cortex - pyelonephritis
usually spares glomeruli and vessels |
|
|
A patient with fever, CVA tenderness, and white cell casts in the urine is at risk for what more serious condition?
|
renal papillary necrosis
the patient has pyelonephritis |
|
|
A patient being treated with ampicillin for a bacterial infection develops fever, rash, eosinophilia, and hematuria a few weeks after starting the medicine. What is causing his symptoms?
|
drug-induced acute interstitial nephritis
|
|
|
Granular casts in the urine are seen in what type of necrosis?
|
acute tubular necrosis
|
|
|
What causes postrenal acute renal failure?
|
bilateral outflow obstruction
|
|
|
Acute tubular necrosis is the most common cause of what major condition?
|
intrinsic acute renal failure
|
|
|
Urine osmolality is high in what type of acute renal failure?
|
prerenal
|
|
|
Urine sodium is low in what type of acute renal failure?
|
prerenal due to retension of Na by the kidneys
|
|
|
What lab measurement can best differentiate intrinsic from postrenal acute renal failure?
|
BUN/Cr ratio
<15 in intrinsic renal >15 in postrenal |
|
|
Why does chronic renal failure cause anemia?
|
failure of kidney to make erythropoietin
|
|
|
What are the acid/base consequences of renal failure?
|
metabolic acidosis due to decreased acid secretion and decreased generation of bicarb
|
|
|
What is Fanconi's syndrome
|
defective proximal tubule transport of amino acids, glucose, phosphate, uric acid, protein, and electrolyes
|
|
|
A mutation in the APKD1 gene is associated with what diseases other than its primary disease?
|
polycystic liver disease, berry aneurysms, mitral valve prolapse
primary disease is adult polycystic kidney disease |
|
|
What is the genetic difference between adult and infantile polycystic kidney disease?
|
adult - autosomal dominant
infantile - autosomal recessive |
|
|
A patient undergoes a CT scan with an incidental finding of cysts in the renal cortex. What is the patient at risk for?
|
nothing - simple cysts are benign
|
|
|
Compare medullary cystic disease and medullary sponge disease.
|
cystic - medullary cysts, small kidneys, poor prognosis
sponge - collecting duct cysts, good prognosis |
|
|
A patient received dialysis for chronic renal failure is at risk for cysts in what part of the kidney?
|
dialysis cysts - cortical and medullary
|
|
|
A patient with hypertension had a bad reaction to furosemide. What diuretic could the patient be given instead?
|
ethacrynic acid - not a sulfonamide, so no sulfa allergy
|
|
|
The pacemaker of the heart is supplied by which coronary artery in most cases?
|
right coronary artery
|
|
|
In coronary artery occlusion, what structure is most vulnerable to ischemia?
|
anterior interventricular septum supplied by the left anterior descending artery - most common site of coronary artery occlusion
|
|
|
A patient has a history of rheumatic fever. At what intercostal space should you little especially carefully?
|
5th intercostal space at midclavicular line - mitral area (apex of heart) - listen for rumbling late diastolic murmur of mitral stenosis
|
|
|
A patient taking propranolol can expect what change in his cardiac output?
|
Decreased cardiac output
beta blockers decrease cardiac contractility and stroke volume CO = SV x HR |
|
|
What 3 factors can influence stroke volume?
|
contractility, afterload, preload
|
|
|
The ventricular end-diastolic volume is the same as what?
|
preload
|
|
|
How can cardiac afterload be calculated?
|
afterload = MAP = CO x TPR = 2/3(diastolic pressure) + 1/3(systolic pressure)
|
|
|
What would increase the mean arterial pressure more: a 10mmHg increase in diastolic pressure or a 10mmHg increase in systolic pressure?
|
diastolic pressure - heart is in diastole 2/3rds of the time and systole 1/3rd of the time
|
|
|
Describe the influence of heart rate on cardiac output.
|
CO increases as a result of increased HR, except at very high HR, when diastole is not long enough for complete ventricular filling (decreased preload)
|
|
|
The right ventricle is supplied by which artery?
|
acute marginal artery
|
|
|
What is the major source of coronary circulation reserve?
|
R2 - microcirculatory resistance
|
|
|
At equal blood flow rates, a patient with hereditary spherocytosis will have high, same, or low MAP relative to the normal population?
|
high
P = Q x R Spherocytosis increases viscosity of blood, which increases R |
|
|
In the normal cardiac cycle, put the following in order:
mitral valve opens mitral valve closes aortic valve opens aortic valve closes |
1. mitral valve closes
2. aortic valve opens 3. aortic valve closes 4. mitral valve opens |
|
|
In the normal cardiac cycle, the point where left ventricular pressure peaks can be auscultated by listening for what heart sound?
|
S2
|
|
|
An S3 is audible during which phase of the left ventricular cardiac cycle?
|
early diastole - rapid ventricular filling
|
|
|
S1 and S2 both sound similar in ASD and aortic stenosis, but they are different in what way?
|
ASD - A2 before P2
aortic stenosis - P2 before A2 - paradoxical splitting |
|
|
The QRS complex on ECG occurs concurrently with what heart sound?
|
S1
|
|
|
A high pitched diastolic murmur is caused by what left ventricular valve defect?
|
aortic regurgitation
|
|
|
What cardiac abnormalities cause holosystolic murmurs?
|
mitral regurgitation, tricuspid regurgitation, ventricular septal defect
|
|
|
In aortic regurgitation, a systolic murmur is heard due to what?
|
forward flow of regurgitant volume across the aortic valve
systolic murmur is secondary primary murmur is diastolic, due to backward flow of blood from aorta to left ventricle |
|
|
The most frequent lesion of the cardiac valves sounds like what on auscultation?
|
mitral prolapse - late systolic murmur with midsystolic click
|
|
|
A continuous, machine-like murmur is characteristic of what cardiac abnormality?
|
patent ductus arteriosus
|
|
|
Why is the cardiac myocyte resting potential lower than neuronal resting potential?
|
K+ leak current during phase 4 causes K+ to leak out of the cell
|
|
|
What causes the plateau phase of the cardiac ventricular action potential?
|
Ca influx through voltage gated Ca channels balance the efflux of K+ during phase 2, resulting in plateau
|
|
|
The ion entering the cardiac myocyte during phase 2 of the ventricular action potential causes myocyte contraction by what mechanism?
|
Ca influx during phase 2 triggers Ca release from sarcoplasmic reticulum to activate myocyte contraction
|
|
|
How do cardiac myocytes all contract at the same time?
|
gap junctions result in electrical coupling
|
|
|
Depolarization at the SA node is mediated by what ion?
|
opening of voltage-gated Ca channels causes influx of calcium - slower velocity influx than Na channels
|
|
|
What is the mechanisms of automaticity in the cardiac pacemakers?
|
Funny current (If) - slow depolarization by Na current until voltage-gated Ca channels are activated to initiate upstroke
|
|
|
Increasing the flow of funny current in the SA node will have what affect on heart rate?
|
Increased HR due to higher rate of diastolic depolarization
|
|
|
The rate of depolarization at the SA node can be measured on the ECG by what values?
|
P-P interval
|
|
|
The QT interval measures what heart quality?
|
mechanical ventricular contraction
|
|
|
Phase 3 of the SA node action potential can be seen by what ECG characteristic?
|
none - phase 3 is atrial repolarization, which is masked by the QRS complex
|
|
|
If the R-R interval is twice as long as the P-P interval on an ECG tracing, what does that mean?
|
dropped heart beat
|
|
|
A delta wave on ECG is characteristic of what condition?
|
Wolff-Parkinson-White syndrome - accessory conduction pathway from atria to ventricle that bypasses the AV node
|
|
|
A 22 year old male has a ventricular rate of 74 beats per minute and a QT interval of 0.60 sec. What condition is he at risk for?
|
Torsades des pointes due to long QT syndrome
QTc = QT/(RR)^0.5 RR = 60/74 = 0.81 QTc = 0.6/0.9 = 0.66 sec QTc > 0.45 sec is abnormal |
|
|
How can atrial flutter and atrial fibrillation be distinguished on ECG?
|
flutter - regular spacing of QRS complexes, sawtooth appearance of flutter waves
fibrillation - irregularly spaced QRS complexes, no discrete P waves |
|
|
Compare the appearance of 1st degree SA block from 1st degree AV block on ECG?
|
SA block cannot be seen on ECG because SA conductance is masked
AV block - PR interval > 200 ms |
|
|
A patient's ECG tracing reveals progressive lengthening of the PR interval, with a beat eventually being dropped. What type of heart block is this?
|
2nd degree AV block - Mobitz type 1 (Wenckebach)
|
|
|
A patient's ECG tracing shows regularly spaced P waves. The RR interval is 1.6 sec and the PP interval is 0.8 sec. What is wrong in this patient?
|
Mobitz type II 2nd degree 2:1 AV block (every other P wave conducts to a QRS)
|
|
|
Complete heart block is characterized by what ECG pattern?
|
P waves and QRS complexes are present, both occur independently of each other, so the atria and ventricles are both beating independently of each other
|
|
|
A person in ventricular fibrillation should receive what treatment?
|
immediate CPR and defibrillation
|
|
|
What organ systems regulate the mean arterial pressure?
|
Kidneys via RAA
Heart and vasculature via sympathetic activity |
|
|
The cranial nerve that regulates salivation from the parotid gland also regulates HR and BP via what receptors?
|
Carotid sinus baroreceptors and chemoreceptors transmit signals via the glossopharyngeal nerve
|
|
|
In severe hemorrhage, decreased afferent baroreceptors signals will have what effect on efferent sympathetic and parasympathetic firing?
|
Decrease afferent baroreceptor firing in response to low BP, so:
efferent sympathetic firing will increase efferent parasympathetic firing will decrease net result is vasoconstriction, increased HR, increased contractility, and increased BP |
|
|
How do baroreceptors in the aortic arch respond to hypotension?
|
they don't - aortic arch baroreceptors only respond to increase in BP (increased stretch)
|
|
|
Pulmonary capillary wedge pressure greater than 12 mmHg indicates what?
|
high left atrial pressure
|
|
|
How does the pulmonary vasculature respond to hypoxia?
|
Vasoconstriction
In all other organs, hypoxia causes vasodilation |
|
|
In calculating capillary fluid exchange, endothelial damage will have what result on Kf and net fluid flow?
|
Kf = capillary permeability
endothelial damage increases Kf Net fluid flow depends on net filtration pressure |
|
|
What is the equation for calculating net filtration pressure in capillary fluid exchange?
|
P(net) = [(Pc-Pi) - (PIc-PIi)]
Pc = capillary pressure (pushes fluid out of capillary) Pi = interstitial fluid pressure (pushes fluid into capillary) PIc = plasma colloid osmotic pressure (pulls fluid into capillary) PIi = interstitial fluid colloid osmotic pressure (pulls fluid out of capillary) |
|
|
Edema is favored by increasing what variables in capillary fluid exchange?
|
Kf, Pc, PIi
|
|
|
Patients with liver failure have edema because of what?
|
decreased protein production --> decreased plasma proteins --> decreased plasma colloid osmotic pressure
|
|
|
Early cyanosis is caused by what type of congenital heart diseases, and what is the direction of the shunt?
|
R --> L shunt
5 T's: Tetralogy of Fallot Truncus arteriosus Transposition of great arteries Tricuspid atresia Total anomalous pulmonary venous return (TAPVR) |
|
|
A cyanotic 9 year old boy has a loud S1 and a wide, fixed, split S2. What direction heart shunt was he born with?
|
ASD: L --> R shunt
he is cyanotic now because if Eisenmenger's syndrome (reversal of L --> R shunt due to progressive pulmonary HTN) |
|
|
What is the most common congenital cardiac anomaly?
|
VSD
|
|
|
A patient born with congenital pulmonary stenosis, right ventricular hypertrophy, an overriding aorta, and a VSD had abnormal development of what cardiac structure?
|
Tetralogy of Fallot - anterosuperior displacement of the infundibular septum
|
|
|
Why should children with cyanotic congenital heart defects be trained to squat?
|
Squatting improves cyanotic symptoms by compressing the femoral artery, which increases systemic vascular resistance to decrease the R --> L shunt and deliver more blood from the RV into the lungs rather than systemic circulation
|
|
|
A patient is born with a RV that delivers blood to the aorta, and a LV that delivers blood to the pulmonary arteries, and a patent ductus arteriosus. This patient will only be able to live if the physicians do what?
|
PDA is the only shunt that connected systemic and pulmonary circulation, so patient should be treated with Prostaglandin E to maintain patency of the ductus arteriosus
|
|
|
An adult patient presents with extreme hypertension, but his femoral pulses are very weak. He likely has stenosis where?
|
Adult type coarctation of the aorta involves stenosis distal to the ligamentum arteriosum
Infantile type stenosis is proximal to ligamentum arteriosum (ductus arteriosus) |
|
|
A patient with genotype 45, XO is at a higher risk for what heart defect?
|
coarctation of the aorta
45, XO = Turner's syndrome |
|
|
A woman with diabetes becomes pregnant. What cardiac condition is her child at risk for?
|
Transposition of great arteries
|
|
|
Aortic insufficiency is a late complication of what disease that involves a defect in the fibrillin gene?
|
Marfan's syndrome
|
|
|
Most cases of hypertension are caused by what?
|
90% primary hypertension (essential hypertension)
related to increased CO or TPR |
|
|
What is the definition of hypertension
|
BP > 140/90
|
|
|
Xanthomas are a sign of an increase of what substance in the body?
|
Lipids
|
|
|
Fibrous plaques in the intima of arteries are referred to as what?
|
Atherosclerosis - atheromas
|
|
|
Patients with carotid artery disease are at risk for what complication?
|
stroke due to thromboembolism or plaque fragment blocking arteries or due to low flow through a very stenotic segment
|
|
|
Carotid artery plaques are most likely to form where?
|
carotid bulb - the only bifurcation in the body that is normally dilated
|
|
|
A patient with a history of HTN presents with tearing chest pain that radiates to his back. What do you expect to see on his CXR?
|
mediastinal widening due to aortic dissection
|
|
|
What triad of symptoms are seen in ruptured aortic aneurysm?
|
pain, hypotension, pulsatile mass
|
|
|
Atherosclerosis involves what types are arteries?
|
elastic arteries, large & medium size muscular arteries
|
|
|
Describe the pathogenesis of atherosclerosis.
|
endothelial cell dysfunction --> macrophage & LDL accumulation --> foam cells --> fatty streaks --> smooth muscle migration --> fibrous plaque --> complex atheroma
|
|
|
The most common location for atherosclerosis is where?
|
abdominal aorta
|
|
|
A ruptured atherosclerotic plaque results in decreased blood flow. What is this called?
|
acute coronary syndrome
|
|
|
Myocardial infarction is an acute onset of what disease?
|
Ischemic heart disease - cardiac supply cannot meet demand
|
|
|
When coronary microcirculation is maximally dilated, an increase in heart rate will cause what symptom?
|
Angina - coronary blood flow cannot increase sufficiently to meet demand
|
|
|
What part of the heart is most vulnerable to ischemic heart disease?
|
subendocardium - R2 reserve runs out in subendocardium first
|
|
|
Stable angina is due to what?
|
atherosclerosis
|
|
|
What is Prinzmetal's variant angina?
|
angina that occurs at rest due to coronary artery spasm
|
|
|
A patient with an atherothrombotic occlusion of the left anterior descending artery dies en route to the hospital. What did he die of?
|
cardiac arrhythmia secondary to myocardial infarction
|
|
|
Is a cardiac infarct red or pale?
|
Pale - heart has single blood supply without collateral circulation, so hemorrhagic infart will not occur
|
|
|
Cardiac muscle has its lowest degree of integrity and is at highest risk for rupture and cardiac tamponade during what time period after an MI?
|
2-4 days
|
|
|
Eosinophils are seen in cardiac muscle fibers during what time period after an MI?
|
first day
|
|
|
Hyperemia, neutrophil emigration, and coagulative necrosis is seen how many days or weeks after an MI?
|
2-4 days
|
|
|
A week after an MI, what inflammatory cells will be seen in cardiac muscle fibers?
|
neutrophils and macrophages
|
|
|
Months after an MI, scar formation is complete, cardiac muscle is no longer at high risk of rupture, but may be at risk for what?
|
ventricular aneurysm
Dressler's syndrome - autoimmune fibrinous pericarditis |
|
|
The best serum marker for cardiac MI is what?
|
Troponin I
|
|
|
What ECG findings are characteristic of a transmural myocardial infarct?
|
ST segment elevation
pathological Q waves |
|
|
A patient with elevated cardiac troponin I and ST segment depression likely had what?
|
subendocardial infarct
|
|
|
A VSD that occurs after an MI is due to rupture of what structure?
|
interventricular septum
|
|
|
Papillary muscle damage following an MI can result in what?
|
severe mitral regurgitation
|
|
|
A patient with hyperemia and coagulative necrosis of the myocardium has a friction rub. What is causing this?
|
Fibrinous pericarditis about 3-5 days post-MI
|
|
|
What is the most common type of cardiomyopathy?
|
Dilated cardiomyopathy
|
|
|
Systolic dysfunction in an alcoholic patient occurs in what type of cardiomyopathy?
|
dilated cardiomyopathy
|
|
|
Both dilated and restrictive cardiomyopathy involve decreased LV function, CO, and SV. What is an important hemodynamic distinguishing factor between these two cardiomyopathies?
|
dilated - increased preload
restricted - decreased preload |
|
|
Sarcoidosis, amyloidosis, and post-radiation fibrosis are all risk factors for what cardiomyopathy?
|
restrictive
|
|
|
How does the heart remain a normal size despite significant hypertrophy in hypertrophic cardiomyopathy?
|
Hypertrophy of the interventricular septum occurs, which pushes into the ventricular space
|
|
|
A high school basketball player suddenly falls during a game and immediately dies. What did he die of?
|
hypertrophic cardiomyopathy
|
|
|
Why are patients with hypertrophic cardiomyopathy at risk for ischemic heart disease?
|
oxygen demands of hypertrophic heart cannot be met by coronary blood supply
|
|
|
How is congestive heart failure different from ischemic heart disease?
|
CHF - cardiac blood supply fails to meet the demands of the body
IHD - coronary blood supply fails to meet the demands of the heart |
|
|
What are heart failure cells?
|
hemosiderin-laden macrophages - can be found in the lungs in left ventricular failure
|
|
|
Why do patients with CHF sleep on 2-3 pillows?
|
supine position increases venous return to the heart, which exacerbates pulmonary vascular congestion in CHF, leading to orthopnea
using multiple pillows allows the force of gravity to decrease venous return to alleviate the orthopnea |
|
|
An increase in venous pressure can cause edema and elevated JVP in what heart problem?
|
right heart failure
*remember right heart failure --> increased venous pressure |
|
|
A patient returned home from a trip to Europe two days ago, and has been experiencing chest pain, and difficulty breathing. Her respiratory rate is elevated. What should she be treated with?
|
Anticoagulants - trio of chest pain, tachypnea, and dyspnea are seen in pulmonary embolism - recent air travel increases suspicion
|
|
|
What is Virchow's triad?
|
stasis, hypercoagulability, and endothelial damage
predisposes to deep vein thrombosis |
|
|
A 10 year old has just recently recovered from strep throat. The child is brought in again to the doctor because of skin rash, abdominal pain, and dark tarry stools. What type of immunoglobulins are causing these symptoms?
|
IgA - Henoch Schonlein purpura
|
|
|
A 12 year old girl is infected with group A beta hemolytic strep. She has fever, swelling of her joints, and myocarditis. Her physician tells her she is at risk for having heart trouble in the future because of this infection. What immunologic mechanism would cause her future heart trouble?
|
Rheumatic heart disease - type II hypersensitivity reaction
Reinfection with strep species activates antibodies that act against both the strep and her heart |
|
|
A patient with a history of heroin use presents with fever, white spots on his retina with some retinal hemorrhage, raised lesions on his fingers that are tender to palpation, and erythematous lesions on his palms. What cardiac finding will he probably have?
|
tricuspid valve endocarditis
indicated by: iv drug use, fever, roth's spots (retina), osler's nodes (tender lesions on fingers), and Janeway lesions (erythematous lesions on palms) |
|
|
A patient with a history of mitral stenosis presents to the physician after having difficulty sewing. She said at times the pads of her fingers would become somewhat tender and bumpy. She sometimes also got rashes on the palms of her hands, but they never troubled her enough to seek care. She has a low-grade fever and does not take any medications except for some pain medication 6 months ago after a root canal. What pathogen is most likely causing her symptoms?
|
Viridans streptococcus
Symptoms consistent with subacute bacterial endocarditis: previously damaged valve (mitral stenosis), recent dental work, osler's nodes and janeway lesions, subacute presentation |
|
|
A patient with a history of SLE presents to the physician with dyspnea. Cardiac exam reveals a friction rub, Kussmaul's pulse, and distant heart sounds. The substance causing these symptoms is composed of
A. fibrin-rich exudate B. fibrin-rich transudate C. bacterial pathogen D. inflammatory infiltrates E. protein-rich exudate F. protein-rich transudate |
E. protein-rich exudate
SLE can cause SEROUS pericarditis, which is rich in protein fibrinous pericarditis is rich in fibrin hemorrhagic pericartidis contains inflammatory infiltrates |
|
|
A patient with bacterial endocarditis caused by S. aureus infection likely had what cardiac valve structure prior to the infection?
|
Normal cardiac valve structure
S. aureus --> acute bacterial endocarditis - large vegetations on normal valves |
|
|
A patient with dyspnea has a BP of 90/60, elevated JVP, distant heart sounds, and weak pulses. Her pulse seems to become weaker when she inspires. What is causing her symptoms?
|
Cardiac tamponade - compression of heart by fluid
|
|
|
A young woman who recently immigrated from China presents with fever, joint pains, muscle aches, and changes in vision. Physical exam revealed pulses that are weaker in her arms than her legs. What does she have?
|
Takayasu's arteritis
|
|
|
Both aortic coarctation and Takayasu's arteritis involve weak pulses. How can these be differentiated?
|
Coartation - weak pulses in lower extremities
Takayasu - weak pulses in upper extremities |
|
|
Granulomatous necrosis of the lung and upper airway, vascular necrosis, and hematuria involves what antibody?
|
c-ANCA - Wegener's granulomatosis
|
|
|
Granulomatous vasculitis with eosinophilia involves what antibody?
|
p-ANCA - Churg-Strauss syndrome
|
|
|
How are lesions in Henoch-Schonlein purpura different from those in Polyarteritis nodosa?
|
HSP lesions are all the same age
PAN lesions are of different ages |
|
|
Libman-Sacks endocarditis is seen in patients with what disease?
|
SLE
|
|
|
Polyarteritis nodosa is associated with what infectious disease?
|
Hepatitis B
|
|
|
Raynaud's phenomenon is primarily caused by
A. Thrombosis of microvasculature in the fingers B. Vasospasm of small arteries and arterioles C. Decreased cardiac output to the extremities D. Agglutination of blood in cold weather E. Autoimmune destruction of capillaries |
B. Vasospasm of small arteries and arterioles
|
|
|
Segmental thrombosing vasculitis of small and medium peripheral arteries and veins in heavy smokers is best treated with what?
|
Smoking cessation
Buerger's Disease |
|
|
Tuberous sclerosis is associated with what cardiac tumor?
|
Rhabdomyoma
|
|
|
Vasculitis affecting the skin, joints, and GI tract is found in what patient population?
|
children - Henoch Schonlein purpura
|
|
|
Vasculitis with p-ANCA that does not cause granuloma is called what?
|
Microscopic polyangiitis
|
|
|
What are the classic symptoms of bacterial endocarditis?
|
FROM JANE:
Fever Roth's spots Osler's nodes Murmur Janeway lesions Anemia Nail-bed damage Emboli |
|
|
What are the JONES criteria for rheumatic heart disease?
|
Joints (migratory polyarthritis)
O-shaped heart (dilated) Nodules (Aschoff bodies) Erythema marginatum Syndenham's chorea |
|
|
What are the symptoms of temporal cell arteritis?
|
unilateral headache, jaw claudication, impaired vision
|
|
|
What fever pattern is seen in Kawasaki disease?
|
remittant spiking fevers
|
|
|
What is a cardiac complication of treponema pallidum infection?
|
Syphilitic heart disease
|
|
|
What is Kussmaul's pulse?
|
weak pulse that decreases in amplitude during inspiration
|
|
|
What is Sturge-Weber disease?
|
congenital vascular disorder of small vessels and capillaries
port wine stain on face leptomeningeal angiomatosis |
|
|
What part of the heart is damaged in syphilitic heart disease?
|
Vasa vasorum of aorta - can cause aortic aneurysm, valve incompetence, or calcification
|
|
|
Where is the most common site of adult primary cardiac tumors?
|
left atrium - myxoma
mitral valve obstruction can impair ventricular filling |
|
|
What are the 5 classes of antihypertensive drugs?
|
Diuretics, Sympathoplegics, Vasodilators, ACE inhibitors, Angiotensin II receptor inhibitors
|
|
|
What is the mechanism of action of thiazide diuretics?
|
Inhibit NaCl reabsorption in the early distal convoluted tubule
|
|
|
Thiazide and loop diuretics both can cause hypokalemia. What metabolite is excreted in one and conserved in the other?
|
Ca - excreted in loop diuretics, conserved in thiazides
|
|
|
What antihypertensive agent acts in the nephron to eliminate hypertonicity in the medulla?
|
Furosemide (loop diuretic)
|
|
|
Change in hearing can be a side effect of what antihypertensive medication?
|
Furosemide (loop diuretic)
|
|
|
What is the mechanism of action of loop diuretics?
|
Block Na/K/2Cl cotransport in the thick ascending limb of the loop of henle
|
|
|
Metabolic alkalosis is a side effect of what diuretics?
|
thiazides and loop diuretics
|
|
|
What is the mechanism of action of spironolactone?
|
Inhibit aldosterone receptor to prevent Na and water loss in the collecting tubule
|
|
|
Which antihypertensive medication can cause a positive Coomb's test
|
Methyldopa
|
|
|
Which diuretic is preferred for treatment of mild hypertension, and which is preferred for treatment of moderate to severe hypertension?
|
thiazides for mild, loop diuretics for moderate to severe
|
|
|
Describe the general cardiac actions of sympathetic stimulation? (Hint: consider how these are utilized for antihypertensives)
|
increase venous tone
increase cardiac output increase heart rate increase cardiac contractile force increase total peripheral resistance |
|
|
What antihypertensive agents are alpha-2 receptor agonists?
|
Clonidine, Methyldopa
|
|
|
How does clonidine reduce blood pressure?
|
decrease cardiac output and vascular resistance
|
|
|
Hexamethonium is very effective at decreasing blood pressure. Why isn't it used in clinical practice?
|
it is a ganglionic blocker that blocks nicotinic ACh receptors, thus has many severe side effects
|
|
|
What is guanethidine's mechanism of action?
|
deplete NE storage and release from adrenergic nerve terminals
|
|
|
Treatment with reserpine for hypertension would decrease the concentration of what neurotransmitter at its site of action?
|
Norepinephrine
|
|
|
Why is the alpha receptor blocker prazosin used to treat HTN but alpha blocker phentolamine is not?
|
phentolamine is a nonselective alpha antagonist and is associated with excessive compensatory tachycardia
prazosin is a selective alpha-1 antagonist and does not demonstrate this compensatory response |
|
|
What is the main cardiac effect of prazosin in treating HTN?
|
decrease vascular resistance and venous return
|
|
|
Elevated lipids and glucose are side effects of what antihypertensive medications
|
beta blockers
|
|
|
What are the mechanisms of reducing hypertension of the different kinds of vasodilators?
|
release NO
open K+ channels --> hyperpolarization block Ca channels activate D1 dopamine receptors |
|
|
What is the mechanism of action of hydralazine?
|
release NO from endothelial cells of arterioles to cause vasodilation
|
|
|
Minoxidil has what effect on vascular smooth muscle?
|
opens K+ channels to hyerpolarize them and thus increase relaxation
|
|
|
What side effect of minoxidil has become a marketing tool for a new drug use?
|
hirsutism - minoxidil is marketed as rogaine
|
|
|
What is the mechanism of action of Verapamil?
|
Ca channel blocker at vascular endothelial cells causes vascular relaxation
|
|
|
What Ca channel blockers are used to treat HTN?
|
Nifedipine, verapamil, diltiazem
|
|
|
Although both nitroprusside and hydralazine cause vasodilation by stimulating NO action on endothelial cells, what is a difference in their mechanisms?
|
nitroprusside is the source of NO (ie the drug itself), whereas hydralazine stimulates endogenous NO release from endothelial cells
|
|
|
What second-messenger system is activated by nitroprusside?
|
cGMP
|
|
|
What is the mechanism of action of diazoxide?
|
open K+ channels to hyperpolarize endothelial cell membrane and cause vascular relaxation
|
|
|
Why is diazoxide contraindicated in patients with diabetes?
|
diazoxide can reduce insulin release and cause hypoglycemia
|
|
|
What is appropriate use of the antihypertensive drug that acts on D1 receptors?
|
Fenoldopam - use for hypertensive emergencies
|
|
|
What side effect of captopril is due to increased bradykinin release?
|
cough
|
|
|
What antihypertensive drugs will decrease levels of angiotensin II?
|
ACE-inhibitors - captopril, enalapril, fosinopril
|
|
|
What is the mechanism of action of losartan?
|
competitive inhibitor of the angiotensin II receptor (AT1)
|
|
|
Why is hydralazine contraindicated in patients with angina?
|
vasodilation can result in compensatory tachycardia
|
|
|
Nitroglycerin relieves angina pain by what mechanism?
|
release NO in smooth muscle to cause smooth muscle relaxation --> this decreases venous return to the heart (decreased preload) and decreased myocardial oxygen demand
|
|
|
What lipid-lowering agents decrease synthesis of cholesterol?
|
Statins (HMG-CoA reductase inhibitors)
|
|
|
What lipid-lowering drug decreases intestinal reabsorption of cholesterol?
|
ezetimibe
|
|
|
How does vitamin B3 decrease cholesterol?
|
Niacin (B3) inhibits hepatic secretion of VLDL into circulation
|
|
|
The red, flushed face side effect of a lipid-lowering agent can be reduced by taking what other drug?
|
aspirin
(flushed face is a niacin side effect) |
|
|
What lipid-lowering agents will increase the concentration of lipoprotein lipase?
|
Fibrates - gemfibrozil, clofibrate, bezafibrate, fenofibrate
upregulate LPL to increase triglyceride clearance |
|
|
What is the mechanism of action of cholestyramine?
|
bile acid resin - prevent intestinal absorption of bile acids to force liver to utilize cholesterol to make more
|
|
|
What are the 4 classes of antiarrhythmic drugs
|
1. Na channel blockers
2. Beta blockers 3. K channel blockers 4. Ca channel bockers |
|
|
Class 1a, 1b, and 1c antiarrhythmics have what affect on cardiac action potential duration?
|
1a - prolong AP duration
1b - shorten AP duration 1c - no affect on AP duration |
|
|
What are the class 1a antiarrhythmic drugs
|
quinidine, amiodarone, procainamide, disopyramide
"Queen Amy Proclaims Diso's Pyramid" |
|
|
What types of arrhythmias can class 1a drugs correct?
|
both atrial and ventricular - reentrant, ectopic, supraventricular, v.tach
|
|
|
What are the class 1b antiarrhythmic agents?
|
Lidocaine, Mexiletine, Tocainide
|
|
|
Lidocaine is the agent of choice for what cardiac arrhythmia?
|
v.tach
|
|
|
Arrhythmia caused by digitalis can be treated by what agents?
|
class 1b antiarrhythmics
|
|
|
How do class 1 antiarrhythmics affect the slope of phase 4 depolarization in the heart?
|
decrease slope (ie slow down depolarization)
|
|
|
What is a major cardiac side effect of class 1a antiarrhythmics?
|
torsades de pointes from increased QT interval
|
|
|
What agents are class 1c antiarrhythmics?
|
Flecainide, Ecainide, Propafenone
|
|
|
Class 1c antiarrhythmics are contraindicated for what disease?
|
contraindicated post-MI - can be pro-arrhythmic
|
|
|
What is the main use of the antiarrhythmic flecainide?
|
last resort for refractory tachyarrhythmias
|
|
|
Class 2 antiarrhythmics are most effective in what cardiac abnormalities?
|
slow ventricular rate during a.fib and a.flutter - AV node is particularly sensitive to beta blocker effects
|
|
|
What are the agents in class 3 antiarrhythmics?
|
bretylium, ibutilide, amiodarone, sotalol
|
|
|
What parts of the cardiac action potential are affected by beta blockers?
|
increase PR interval, decrease phase 4 depolarization slope
|
|
|
How do class 3 antiarrhythmics protect against tachycardia?
|
increase AP duration by decreasing the rate of phase 3 repolarization by K current
|
|
|
What labs should be checked in patients taking amiodarone?
|
PFT, LFT, TFT (pulm, liver, thyroid function tests)
|
|
|
What class 3 antiarrhythmics are associated with risk of torsades de pointes?
|
sotalol, ibutilide
|
|
|
Where is the cardiac site of action of class 4 antiarrhythmics?
|
AV node
|
|
|
Verapamil will affect cardiac action potentials in what way?
|
increase PR interval, increase refractory period, decrease conduction velocity
|
|
|
Why is nifedipine not part of the class 4 antiarrhythmics?
|
nifedipine blocks Ca channels in peripheral vascular smooth muscle cells, whereas verapamil and diltiazen preferentially act centrally in the heart
|
|
|
What is the drug of choice to diagnose or abolish AV nodal arrhythmia?
|
adenosine (not part of 4 classes of antiarrhythmics)
|
|
|
What is the structure of respiratory epithelium?
|
pseudostratified ciliated columnar epithelial cells
|
|
|
What is the function of type II pneumocytes?
|
secrete surfactant, precursor to type I pneumocytes, proliferate during lung damage
|
|
|
Where in the respiratory tract are goblet cells found?
|
conducting zone of respiration
|
|
|
Pulmonary fibrosis involves damage to what cells?
|
type I pneumocytes
|
|
|
A tertiary segmental bronchus, a bronchial artery, and a pulmonary artery make up what structure?
|
bronchopulmonary segment
|
|
|
A child chokes on an aspirated foreign object. Where do you expect it to get stuck?
|
right bronchus
|
|
|
The horizontal fissure of the lung separates what structures?
|
right superior lobe and right middle lobe
|
|
|
What nerves innervate the diaphragm?
|
C3, C4, C5 of the phrenic nerve
|
|
|
In normal breathing, what muscle facilitates expiration?
|
trick question - none
quiet breathing involves passive expiration |
|
|
During high activity, what muscles facilitate expiration?
|
rectus abdominus, transversus abdominus, internal and external obliques, internal intercostals
|
|
|
What muscles facilitate inspiration during exercise?
|
external intercostals, scalene muscles, sternomastoids
|
|
|
If a person inhales fully, then exhales up to FRC, what will the pressure in the airways be at FRC?
|
0 - lung pressure is 0 at functional residual capacity
|
|
|
What lung volume does IRV measure?
|
inspiratory reserve volume - amount that can be inspired after tidal volume (normal breathing)
|
|
|
A person inhales as much as they can, then exhales as much as they can, then inhales quietly, then exhales quietly. What was the person's total lung volume at each step?
Hint: not actual numbers |
TLC
RV FRC+TV FRC |
|
|
A person inhales quietly, then exhales as much as they can, then inhales quietly, then exhales quietly. What was the difference in the person's lung volume after each expiration?
|
FRC - ERV = RV
|
|
|
What is physiologic dead space?
|
volume of inspired air that does not take part in gas exchange
anatomical dead space + functional dead space |
|
|
What is the different between anatomical and functional dead space?
|
anatomical dead space is the parts of the airway that are not in contact with gas exchange structures (ie bronchi, trachea)
functional dead space is parts of the airway that are in contact with gas exchange structures (ie alveoli) but do not take part in gas exchange because of inadequate perfusion in that area |
|
|
How does Hb oxygen affinity change during exercise?
|
decreased Hb oxygen affinity to facilitate unloading of O2 onto tissues
|
|
|
What factors can shift the oxygen-Hb dissociation curve?
|
CADET:
CO2 Acid/Altitude 2,3-DPG Exercise Temperature |
|
|
What does fetal Hb's oxygen dissociation curve look like compared to adults?
|
fetal Hb curve shifted to the left because fetal Hb has higher O2 affinity (this is how fetus sequesters O2 supply from mother)
|
|
|
In all other tissues of the body, decreased PO2 causes vasodilation, but in the lungs it causes vasoconstriction. Why?
|
Vasocontriction allows blood to shift away from poorly ventilated areas to well ventilated ones so that blood can obtain maximum oxygen to deliver to body
|
|
|
CO poisoning has what affect on oxygen unloading in tissues?
|
shifts Hb-O2 dissociation curve to the left --> decreased oxygen unloading
|
|
|
A D-dimer test is used to rule out what problem?
|
pulmonary embolism
|
|
|
Define pulmonary hypertension.
|
Pulmonary artery pressure >25 mmHg at rest or >35 mmHg during exercise
|
|
|
Diffuse alveolar damage occurs when pulmonary fluid flow is not matched by what?
|
lymphatic clearance - Pulmonary edema
|
|
|
An anemic patient will have what differences compared to a normal patient in these variables:
arterial O2 content O2 saturation arterial PO2 |
O2 content will decrease (because less Hb to hold O2)
O2 saturation will not change (because Hb that is available will bind O2 normally) arterial PO2 will not change (because O2 affinity is not changed) |
|
|
What is the A-a gradient?
|
difference between alveolar PO2 and arterial PO2
|
|
|
How can you calculate what normal A-a gradient should be in a patient?
|
(10+age)/4
|
|
|
Where in the lung is perfusion typically wasted?
|
base - blood flow higher in base because of gravity, not matched by same increase in airflow
|
|
|
How would vasodilation in the lung apex affect the V/Q ratio?
|
V/Q ratio would decrease
normally apex has wasted ventilation (V/Q > 1) vasodilation would increase the perfusion, causing V/Q to approach 1 |
|
|
What does it mean if V/Q = 0?
|
there is an airway obstruction resulting in almost no ventilation
|
|
|
A V/Q mismatch causes the A-a gradient to change how?
|
increase
|
|
|
In pulmonary gas exchange, what function marker can help differentiate between a lung problem or a problem elsewhere in the body?
|
A-a gradient (increased in lung dysfunction)
|
|
|
How is most CO2 transported to the lungs from peripheral tissue?
|
bicarbonate in RBCs
|
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The Bohr effect in peripheral tissues has what influence on O2 in RBCs?
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H+ from peripheral tissue metabolism causes the Hb-O2 dissociation curve to shift to the right, resulting in O2 unloading and CO2 loading
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What is the formula for CO2 metabolism in RBCs?
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CO2 + H2O <-> H2CO3 <-> H+ + HCO3-
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How do RBCs know to release CO2 in the lungs but not in peripheral tissue?
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in the lungs, high oxygen levels cause oxygenation of Hb, causing dissociation of H+
excess H+ promotes bicarbonate to form CO2 and release it into lungs |
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Why might a mountain climber suffer respiratory alkalosis as he reaches the top?
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lower O2 content at high altitudes --> mountain climber increases ventilation to compensate
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Obstructive lung disease increases lung volume by what mechanism?
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Obstruction of expiratory air flow traps air inside lungs
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What makes chronic bronchitis an obstructive lung disease?
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hypertrophy of mucus-secreting glands on bronchioles plugs the airway causing obstruction and trapping air in lungs
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Loss of alveolar tethering is characteristic of what lung disease?
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emphysema
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Panacinar emphysema is caused by what?
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alpha-1 antitrypsin deficiency causes loss of a protective anti-protease resulting in alveolar degradation
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Smoking causes what type of emphysema?
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centriacinar
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Why do people with emphysema exhale through pursed lips?
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this increases airway pressure to prevent airway collapse during exhalation
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FEV1/FVC ratios are decreased in what kind of lung disease?
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obstructive
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Hypertrophy of the smooth muscle and reversibility of airway remodeling differentiates which lung diseases?
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asthma from emphysema
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Extrapulmonary causes of restrictive lung disease often include what pathology?
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poor breathing mechanics - either decreased muscular effort or damaged structure of breathing apparatus
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What would the FEV1/FVC ratio be in adult respiratory distres syndrome?
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>80% (restrictive lung disease)
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An increase in alveolar surface tension will result in what change in lung function tests?
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decreased lung volume, FEV1/FVC>80%, restrictive lung disease
neonatal RDS - surfactant deficiency |
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If forced to expire as fast as possible, what percentage of total expiration would occur within the first second?
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FEV1/FVC = 80% in normal individuals
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In obese individuals, what causes airway obstruction in sleep apnea?
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pharyngeal tissue
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Pleural plaques in the lower lung lobes of a smoker will greatly increase the risk for what disease?
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bronchogenic carcinoma due to asbestosis
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Less than an hour after exposure to a seasonal allergen, what is the main mediator of hypersensitivity?
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histamine
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Why is vasodilation bad in sinusitis?
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thick secretions plug up dilated vascular and do not clear
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A patient with lung cancer develops Horner's syndrome. Where is the tumor?
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Pancoast's tumor in lung apex is affecting the superior sulcus of the brachial plexus
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Why is it important to differentiate small cell from non-small cell lung cancer?
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small cell lung cancer is never treated surgically whereas non-small cell lung cancer is
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What lung cancer preferentially occurs centrally?
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squamous cell carcinoma and small cell carcinoma
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Nonsmokers with lung cancer will show histologic abnormality in the cells that produce what substance?
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surfactant
adenocarcinoma involves clara cells and type II pneumocytes, and is not linked to smoking |
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Kulchitsky cells are associated with what lung cancer?
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small cell carcinoma
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What is the general prognosis for the type of lung cancer that involves giant cells?
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large cell carcinoma - poor prognosis
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Carcinoid syndrome in a carcinoid tumor of the lung is caused by secretion of what?
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serotonin
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Gynecomastia is a paraneoplastic syndrome associated with what lung cancer?
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large cell lung cancer
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Pneumococcus causes what type of pneumonia?
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lobar
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Increasing interstitial protein concentration would have what affect in pleural fluid?
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increase fluid into pleural space --> pleural effusion
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What are the 1st generation H1 receptor blockers?
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Diphenhydramine, Dimenhydrinate, chlorpheniramine
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What are the 2nd generation H1 receptor blockers?
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Loratadine, fexofenadine, desloratadine, cetirizine
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What is the main benefit of 2nd generation H1 receptor blockers over 1st generation?
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less sedating effects - decreased entry into CNS
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Beta-2 agonists used to treat asthma use what second messenger system?
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increase adenylyl cyclase --> cAMP
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What are the beta-2 agonists used for asthma and what is the indication for their use?
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albuterol - acute exacerbation
salmeterol - prophylaxis |
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How does theophylline help treat asthma?
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inhibit phosphodiesterase from hydrolyzing cAMP --> increased cAMP causes bronchodilation
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Where is the site of action of the antiasthmatic ipratropium?
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competitive inhibitor of muscarinic receptor prevents bronchoconstriction
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Cromolyn is indicated for treatment of what?
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asthma prophylaxis
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Chronic asthmatics are given what drugs as first-line therapy?
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inhaled corticosteroids - beclomethasone, prednisone
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What is the mechanism of action of the drugs used preferentially for exercise-induced asthma?
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block leukotriene receptors - zafirlukast, monelukast
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Which antiasthmatic inhibits synthesis of leukotrienes?
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zileuton - inhibits arachadonic acid conversion to leukotrienes
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