Reading...
Play button
Play button
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;
17 Cards in this Set
- Front
- Back
|
What reactions normally generate free radicals?
|
normal redox reactions
ie. the Fenton cycle |
|
|
What mechanisms remove free radicals?
|
Antioxidant mechanisms
-SOD (in mitochondria) converts O2* to H2O2 -Glutathione peroxidase (in mitochondria) converts OH* to H2O2 -Catalase (in peroxisomes) convert H2O2 to H2O + O2 |
|
|
Lesions can be ___ and ___?
|
-Pathognomionic - characteristic of cause
-Nonspecific - different processes can cause same lesion |
|
|
What are lesions?
|
Structural alterations due to disease
|
|
|
What are the 3 types of necrosis?
|
-coagulation or coagulative
-liquefaction or liquefactive -Caseous |
|
|
What decides what type of necrosis it is?
|
-depends on tissue type
-depends on disease process ---kidney with coagulative necrosis due to ischemia ---kidney with liquefactive necrosis due to fungal infection |
|
|
What are the features of coagulation necrosis?
|
-obvserved grossly and with LM
-Scaffolding is intact -Cytoplasm is hypereosinophilic -Loss of detail withing cell -Loss of nuclei -if survivable - inflammation in surrounding tissue -tissue may heal by scar or regenteration |
|
|
What are the features of Liquefactive necrosis?
|
-observable grossly
-Histologically similar to caseous necrosis -Loss of tissue architecture -WBC and cellular debris -Tissue most susceptible - CNS -Disease process involve destroys tissue ---bacterial infection, fungal infection -Result - cavitation: the formation of cavities within the body, such as those formed in the lung by tuberculosis |
|
|
What are the features of Caseous necrosis?
|
-Observable grossly
-Wxudate has thicker consistency than liquefactive necrosis -Frequently du to bacterial infection - often seen in tuberculosis |
|
|
What activates apoptosis from a pathological vs physiological point?
|
Pathological
--Viral infection --Inflammation may be present due to pathologic process but is not caused by apoptotic cells Physiologic --Embryogenesis --Intestinal epithelial cells --Lymphocytes |
|
|
What is fat necrosis & saponification?
|
saponifacation is changing oils/fats to soap, the condition causes the apperance of soap.
--usually in abdomen --due to leakage of pancreatic enzymes --white chalky deposits are formed from released fatty acids and calcium |
|
|
Does apoptosis require energy?
|
YES
|
|
|
What signals apoptosis?
|
-receptor binding
or -lack of signal to prevent apoptosis |
|
|
Many genes are REGULATORS of apoptosis. Name some and whether they inhibit or stimulate apoptosis.
|
p53 - stimulates
bcl-2 - inhibits bax - stimulates bcl-XL - inhibits bcl-XS - stimulates caspase - promotes fas - stimulates FasL - stimulates |
|
|
What are the biochemical features of apoptosis?
|
activation of caspases (systeine proteases)
crosslinking of cytoplasmic proteins DNA breakdown by endonucleases -internucleosomal cleavage -Ladder appearance in agarose gel electrophoresis (multiples of 180-200 bp) -Not specific Flipping of phosphatidly serine -phagocyte recognition |
|
|
What is the pathway for apoptosis?
|
Trigger - injury, no GH, receptors bind ligand, cytotoxic T cells
Regulators - can either inhibit or promote -caspases - executioners - trigger enzymes to fragment DNA and other fxns -Apoptotic body - cytoplasmic buds break of to be disposed of by macrophages |
|
|
Describe 6 parts of apoptosis morphology
|
nuclear condensation
hypereosinophilia of cytoplasm cell rounds up, often shrinks nucleus is divided into many small dense round bodies membrane bound apoptotic bodies phagocytosis by surrounding cells |
