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15 Cards in this Set
- Front
- Back
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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 |
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Cell injury that leaves the plasma membrane intact
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reversible injury
Also includes swelling, chromatin clumping, autophagy |
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What characterizes irreversible cell injury?
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Defects in plasma membrane, autolysis, nuclear changes: pyknosis, karyolysis, karyorhexis
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Name Nuclear markers of cell death and describe them.
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Pyknosis: very dense, twisted nucleus
Karyorhexis: dense particles of chromatin Karyolysis: dissolved nucleus Other markers include dense calcium bodies in mitochondria |
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Describe the affects of ischemia on the cell.
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-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 |
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If flow is restored to an ischemic area what process can further injure cells?
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Free radical oxidation
Lipid peroxidation, protein damage, DNA damage |
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What are the processes of altered cell growth? Describe them.
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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 |
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What processes does the cell utilize to adapt to different needs and stimuli? Describe them and give an example of the stimulus.
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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. |
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What is the result for a cell which is pushed beyond the limit of adaptation? |
Necrosis
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What are the differences between necrosis and apoptosis?
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Necrosis is unprogrammed and often geographic while apoptosis is programmed and can happen anywhere.
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What gene ratio controls the dichotomy of cell survival versus apoptosis?
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Bcl-2/Bax
Bcl-2 promotes cell survival, Bax promotes apoptosis. |
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Caspases?
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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.
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Apoptosis is activated by what environmental stimuli?
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Developmental morphogenesis
Radiation Immune system regulation Viruses Cancers Toxins |
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What is meant by "losing the ladder" in a DNA Western Blot?
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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.
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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.
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