Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
8 main types of cell injury
|
Genetic - gene defects
Nutritional - lack vitamins Immunologic - aids, autoimmune Endocrine - excess hormone Physical agent - trauma Chemical agent - toxins Infectious agent - viruses Hypoxia - CVD |
|
Cell injury that leaves the plasma membrane intact
|
reversible injury
Also includes swelling, chromatin clumping, autophagy |
|
What characterizes irreversible cell injury?
|
Defects in plasma membrane, autolysis, nuclear changes: pyknosis, karyolysis, karyorhexis
|
|
Name Nuclear markers of cell death and describe them.
|
Pyknosis: very dense, twisted nucleus
Karyorhexis: dense particles of chromatin Karyolysis: dissolved nucleus Other markers include dense calcium bodies in mitochondria |
|
Describe the affects of ischemia on the cell.
|
-Oxidative phosphorylation stops
-Glycogen and creatine phosphate stores used up -ATP depletion -Inability to maintain ion gradients -pH decreases and chromatin condenses -Increased intracellular calcium -Increased Ca activates proteases, lipases which further hurt cell structure -Also activates ATPases which further deplete ATP -Also activates endonucleases which condense and hurt DNA -Coagulative necrosis if flow not restored |
|
If flow is restored to an ischemic area what process can further injure cells?
|
Free radical oxidation
Lipid peroxidation, protein damage, DNA damage |
|
What are the processes of altered cell growth? Describe them.
|
Agenesis: failure of an organ or tissue to develop
Hypoplasia: incomplete development of an organ or tissue Dysplasia: disordered cell growth associated with congential anomalies or pre-malignant growths Hypertrophy: Increased size but not number of cells Hyperplasia: Increased number of cells |
|
What processes does the cell utilize to adapt to different needs and stimuli? Describe them and give an example of the stimulus.
|
Atrophy: reduction in cell size often due to ischemia or disuse.
Hypertrophy: increase in cell size in response to high use or physiologic need such as pregnancy. Involution: reduction in cell number, very important during fetal development, apoptosis. Hyperplasia: Increase in cell number, also do to use, mammary tissue during lactation. Metaplasia: change from one cell type to another due to a need for new characteristics. If repeated trauma is experienced in muscle it can ossify. |
|
What is the result for a cell which is pushed beyond the limit of adaptation?
|
Necrosis
|
|
What are the differences between necrosis and apoptosis?
|
Necrosis is unprogrammed and often geographic while apoptosis is programmed and can happen anywhere.
|
|
What gene ratio controls the dichotomy of cell survival versus apoptosis?
|
Bcl-2/Bax
Bcl-2 promotes cell survival, Bax promotes apoptosis. |
|
Caspases?
|
Caspases are the molecules that carry out apoptosis when Bax exceeds the control of Bcl-2. Caspase activators cleave procaspase molecules which then become caspases which begin the apoptotic cascade.
|
|
Apoptosis is activated by what environmental stimuli?
|
Developmental morphogenesis
Radiation Immune system regulation Viruses Cancers Toxins |
|
What is meant by "losing the ladder" in a DNA Western Blot?
|
DNA from a cell usually provides nice cleavage plains which upon western blot form a ladder appearance on the gel. DNA from an apoptotic cell has been thoroughly cleaved apart by proteases and endonucleases so that a solid uninterrupted line is observed on the western blot.
|
|
You observe a swollen cell featuring large densities in the mitochondria, the rupture of some lysosomes, and a nucleus showing very condensed clumps of chromatin. Can this cell recover from its injury?
|
No, the cell is showing sign of autolysis and karyorhexis which are markers of irreversible cell damage.
|