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101 Cards in this Set
- Front
- Back
the lymphatic system has no
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pump
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3 layers of the CV system (vessels)
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tunica intima (intimate with the blood)
tunica media (muscular) tunica adventitia (supporting layer) |
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3 layers of the heart
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endocardium (tunica intima)
myocardium (tunica media) epicardium (tunica adventitia) |
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parts of the myocardium
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Purkinge fibers + muscle
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the myocardium is thickest when
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the ventricles
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the vessels feeding the aorta in the adventitia are
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vasa vasorum
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3 types of vessels in the arterial system
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elastic
muscular arterioles |
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3 layers of the aorta
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intima
media (predominantly muscle) adventitia |
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vessels in adventitia of heart:
vessels in adventitia of aorta: |
coronary arteries
vasa vasorum |
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flattened cells that embrace the capillary endothelial cells
-may have contractile function found in microcirculation! (capillaries...) |
pericytes
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capillaries with large diameters are called
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sinusoids
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major pressure drop occurs where?
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The major pressure drop occurs in the small arteries & arterioles
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what principle explains:
Blood velocity slows as the cross-sectional area of the vascular bed increases |
conservation of mass
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what's the Ca cycle in cardiac muscle contraction?
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what's the Starling law?
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Imagine an experiment in which the aortic valve is kept shut by a very high pressure in the aorta (afterload)
Maximal isometric pressure generated by ventricle during systole ___ as ventricular end-diastolic volume inc |
inc
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determinants of the left ventricular systolic curve
the left ventricular diastolic curve? |
LV systolic: contractility (ex:coronarry artery thrombosis causes an acute reduction in blood flow to the myocardium that may reduce contractility)
LV diastolic: compliance certain conditions may impair diastolic filling of the ventricle...for example, myocardial ischemia impairs diastolic relaxation, while withstanding HTN causes the LV to grow abnormally thick and stiff.... |
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determinant of LV diastolic curve
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compliance
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determinant of LV systolic curve
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contractility
what would inc contractility? dec? inc: epinephrine, digitalis dec: coronary artery thrombosis |
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Why is it illegal to perform pericardiectomies on greyhounds in the state of FL?
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the pericardium constrains the LV diastolic curve...without it, SV, CO inc
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Contraction results in reduction in circumference and decrease in longitudinal axis with ascent/descent of base of heart
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Atrioventricular (AV) valves: tricuspid & mitral valves -Leaflets are attached to _____, which are attached to ____: prevent eversion during ventricular systole
Semilunar valves: aortic & pulmonic valves |
chordae tendinae
papillary muscles |
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dif bw right side and left side of heart
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The right atrial pressure can be estimated by examining the ______
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jugular venous pressure
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pressure-volume loop
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how does inc in contractility affect SV?
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inc contractility allows ejection to a smaller end-systolic volume...(bc more has pumped out)
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increased preload's effect on SV?
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increases SV by ejecting from a greater LVEDV to the same LVESV (not the inc systolic pressure, due to the Frank Starling mechanism)
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increased afterload's effect on SV?
remember, we just looked at the 3 determinants of SV which are 1) contractility 2) pre-load and 3) after-load |
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how can we measure CO?
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a
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differences in cardiac and skeletal muscle contraction?
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Why do we care about RYR2?
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heart failure
remember the connection between heart failure and “leaky” RYR2 channels |
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The 5-Phases of the Fast-Response AP
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Slow-Response AP (SA, AV Nodes)“The ionic basis of automaticity”
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Ltcc: L-type calcium channel
When skeletal muscle is stimulated by somatic motor axons, influx of Na+ quickly depolarizes the skeletal myocyte and triggers calcium release from the sarcoplasmic reticulum. In cardiac myocytes, the release of Ca2+ from the sarcoplasmic reticulum is induced by Ca2+ influx into the cell through voltage-gated calcium channels on the sarcolemma. This phenomenon is called_______and increases the myoplasmic free Ca2+ concentration causing muscle contraction. In both muscle types, after a delay, (the absolute refractory period), Potassium channels reopen and the resulting flow of K+ out of the cell causes repolarization to the resting state. The voltage-gated calcium channels in the cardiac sarcolemma are generally triggered by an influx in sodium during the "0" phase of the action potential |
calcium-induced calcium release
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dif bw relative and effective refractory periods
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basal rate of SA node
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ectopic atrial foci
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AV node
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Purkinge fibers
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modulators of pacemaker rate
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Cardiac v. Skeletal Muscle APs
3 KEY differences |
Plateau Potentials
--Cardiac AP (~ 300 ms) --Skeletal muscle AP (~ 5 ms) Long duration prevents the fusion of individual twitches (tetany) Cell-to-Cell Conduction (via gap junctions) Automaticity --Intrinsic pacemakers self-generate APs w/o external triggers |
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current flow through gap junctions
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what's the normal conduction pathway
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Slow/fast APs originate in the SA node.
(automaticity) slow/Fast APs propagate through atrial muscle via gap junctions. Slow/fast APs in AV node delay conduction to ventricles Fast/slow APs rapidly depolarize Purkinje and ventricular muscle |
Slow APs originate in the SA node.
(automaticity) Fast APs propagate through atrial muscle via gap junctions. Slow APs in AV node delay conduction to ventricles Fast APs rapidly depolarize Purkinje and ventricular muscle |
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re-entrant conduction
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t/f blood flow through only one capillary bed before it goes back to the heart
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f
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t/f pulsatile flow is maintained only till the end of the aorta
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false
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why don't capillaries rupture?
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small diameter!
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Capillary Blood Pressure (PC) Falls from Approximately __ mm Hg at the Arteriolar End to Approximately ___mm Hg at the Venular End
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35
15 |
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lymphatic drainage:
Terminal lymphs return fluids and proteins to circulation via ____ ______valves. Fluid pumped via _____ |
thoracic duct
One-way skeletal muscle contraction |
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what happens in dehydration, and severe malnutrition in regards to outward pressure and inward pressure
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myogenic response?
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endothelial shear?
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what's the metabolic way of autoregulation?
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what's this?
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Age-related medial degeneration with elastocalcinosis.
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arterial pulse pressure correlates with_____
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stroke volume
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The equilibrium pressure in the circulatory system when Q = 0 is called the
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mean systemic pressure, or Pms*
shown is vascular function curve aka venous return curve |
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what's unstressed volume
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Unstressed volume is the amount of volume needed to “round out” the shape of a vessel before any pressure is generated. Venoconstriction inc the stressed volume.
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how does blood volume chance Pms?
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Changes in resistance alter the slope of the vascular function curve
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what's venous return
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how do we combine the cardiac function curve and the vascular function curve?
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how does a blood transfusion affect the curves?
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how does reduced contractility affect the curves?
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how different factors affect the cardiac response + venous return curves
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this is what hemorrhage without compensation looks like...what does w/compensation look like?
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Imagine an acute dec in LV contractility, as with ischemia.
what happens to RV and LV CO? |
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Young pts with robust compensatory mechanisms can lose a considerable amount of blood before developing hypotension
If you give a drug that reduces _____(for example, morphine) to such a patient, severe hypotension can result. |
venomotor tone
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how can LV failure cause pulmonary edema?
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LV failure can cause pulmonary edema because of elevated pulmonary capillary hydrostatic pressures. Respiratory failure & death can result
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what's SVR?
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okay, so we know that CO= (Parterial-Pvenous)/SVR
SVR= systemic vascular resistance but how do we calculate Parterial...if blood is still pulsatile in the arteries!!! |
mean arterial pressure!
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what are the factors of vascular resistance?
how does viscosity, radius, and vessel length affect resistance exactly?? |
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how does viscosity of fluid affect resistance to flow?
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dif bw laminar and turbulent flow?
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compliance?
how do aa and vv compare? which has greater? |
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where in the vasculature does blood have the smallest velocity?
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capillaries
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where in the vasculature is:
resistance the highest? velocity the lowest? blood volume the lowest? (aa or vv?) pressure the lowest? |
resistance the highest? arterioles
velocity the lowest? capillaries blood volume the lowest? (aa or vv?) aa pressure the lowest? vv |
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2 types of resistance vessels in the skin
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Arterioles: found in apical (glabrous) & nonapical (hairy) skin
Arteriovenous anastamoses: found only in apical (highly thermoregulatory) skin |
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Arteriovenous anastamoses & venous plexus
Found in fingertips, palms of hands, toes, soles of feet, ear, nose, lips…) ____ neural control dominates (no metabolic control or autoregulation) |
Sympathetic
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symp control of skin?
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t/f
The brain is extremely intolerant of ischemia. Fortunately, it directs its own blood flow. |
t
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pH, K+, & adenosine adjust cerebral blood flow to match ______
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metabolic activity
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tell me what angiotension II can do...sorta does alot
i know we tend to care that it stimulates the _____ to produce aldosterone but there's other stuff |
adrenal cortex
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The heart typically receives ~ 5% of cardiac output
Both LCA & RCA originate at root of ____behind aortic valve cusps |
aorta
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LCA supplies LA & LV; divides into
left main artery is the segment between the origin & its bifurcation |
LAD and LCX;
left anterior descending and left circumflex |
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______ occurs in 37% of population & can be found arising off LM between LAD and LCX.
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Ramus intermedius
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RCA supplies ___, ___, and ____
_____ arises from RCA in ~ 85% of pts; from LCX ~ 15% of pts. |
RV & RA plus ~ 1/3 of LV (in most pts).
Posterior descending artery |
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what controls myocardial oxygen supply and demand?
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Regulation of coronary blood flow occurs via
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Physical factors
Neural and neurohormonal factors Metabolic factors |
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when is coronary artery blood flow the highest? the lowest?
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t/f The subepicardium is more sensitive to ischemia than the subendocardium
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false
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effects of symp/para
on SA node AV node myocardium coronary vessels |
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Cardiac sympathetic nerve stimulation leads to:
↑ rate → ↓ time in diastole ↑ contractility → ↑ extravascular compression Coronary vasoconstriction via alpha receptors yet, coronary blood flow increases dramatically! How? |
Reduction in ATP opens K+ATP channels and causes hyperpolarization, leading to reduced Ca entry and coronary smooth muscle relaxation.
Adenosine stimulates endothelial NO release at low concentrations. At high concentrations, adenosine activates K+ATP channels on vascular smooth muscle. |
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how can reduced coronary artery flow lead to cell death?
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How might the following worsen the balance between myocardial oxygen supply & demand?
Tachycardia (fast heart rate) Increased contractility Increased afterload Increase preload |
Increase preload
inc force of contraction with resulting inc oxygen consumption inc chamber size (radius) inc's wall tension inc intracavitary pressure inc's gradient for subendocardial blood flow |
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how do we measure pulmonary vascular resistance?
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in the lung, where is the blood flow the greatest?
top or bottom? |
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zone 1, zone 2, zone 3
which is dead space? |
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t/f
inspiration affects alveolar and extra-alveolar vessels differently |
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name 2 diseases that can raise pulmonary vascular resistance (PVR)
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