Pathology Flashcards
What is ischemia? What tissues are most vulnerable?
Inadequate blood perfusion of a tissue bed. Brain and heart are more vulnerable. E.g. acute myocardial infarction.
What is an infarction?
localized area of necrosis due to circulatory insufficiency
What are the principle events in ischemic cell injury?
1)compromised ATP Synthesis 2) cell swelling - Na+ enters the cell. –>hydropic change. and Blebbling 3) decreased pH in cell. Due to anaerobic glycolysis and build up of lactic acid. 4)organelle distortion. ER dilation, nuclear chromatin clumping, mitochondrial swelling. 5) mitichondrial injury due to rise of Ca2+ in cell.
What are two major changes thought to contribute significantly to irreversible cell injury?
1) mitochondrial can’t generate ATP, can’t regain oxidative phosphorylation 2)critical damage to membrane integrity
What morphological changes can you see of reversible cell injury by EM?
-membrane bleb -mitochondrial swelling with misaligned cristae -dilation of ER with ribosomal detachment -
What morphological changes can you see of reversible cell injury by LM?
hydropic change
What are endogenous sources of ROS?
1) ATP synthesis since O2 is final e- acceptor 2) rxns involving transition metals, e.g. Cu, Fe, Zn 3) NO 4) leukocytes, neutrophils and macrophages produce ROS to kill microbes
What are exogenous sources of ROS?
-radiation -pollutants -drugs -toxic substances
What are the mechanisms of free radical damage?
1)membrane lipid peroxidation–>increased membrane permeability 2)protein oxidation–>protein misfolding, degradation, damage to active sites of enzymes 3)DNA damage
How does our body defend against ROS?
-Detoxifying enzymes -antioxidants e.g. Vit E, A, C
What is reperfusion injury?
After cell injury due to ischemia, if blood flow is restored, can result in increased tissue damage b/c buildup of ROS from circulating leukocytes, a breakdown product of ATP, and incomplete oxygen reduction in damaged but viable mitochonrdia
What are some morphological changes from necrosis seen in the nucleus?
pyknosis-clumping, and shrinkage of nuclear chromatin karyorrhexis-nuclear fragmentation and irregular distribution karyolysis-nuclear dissolution
What are some cytoplasmic changes resulting from necrosis?
-increased eosinophilia (due to denatured protons and loss or RNA)
What are some morphological changes from coagulative necrosis?
1)grossly: necrotic are pale and dry 2)slide: no nuclei, cytoplasmic eosinophilia, preservation of architecture
What are some morphological changes from liquefactive necrosis?
1)from cerebral infarction a)grossly: softens, liquefies b) micro: dead parenchyma dissolution, debris, macrophages 2)from abscess a) grossly: pus filled pocket b)micro: clusters of PMN dead/dying, cellular debris, edema,
What are some morphological changes from dry gangrene?
grossly: black, dry, shriveled
What are some morphological changes from wet gangrene?
when bacterial infection is superimposed on necrosis. Secondary infection of dry gangrene. E.g. in GI tract. Usually fatal
What are some morphological changes from gas gangrene?
extensive necrosis and gas production. caused by clostridium species
What are some morphological changes from caseous necrosis?
grossly: soft, crumbly, looks cheesy micro: highly eosinophilic region, no recognizable parenchyma. can’t say its caseous though.
What are some morphological changes from fat necrosis?
grossly: filmy patchy while chalky areas micro: white deposits with pale outlines of dead fat cells “ghost cells” filled with basophilic Ca deposits.
What is fibrinoid necrosis?
Vessel damaged caused by hypertension, vasculitis, autoimmune disease.
What is anatomical pathology?
study of gross and microscopic changes in cells and tissues caused by disease. Includes: surgical path, cytopath, hematopath, autopsy path
What does surgical pathology analyze?
biopsy and surgical specimens, e.g. diagnosis of malignancy
What does cytopathology look at? What is a sample you would send to such a lab?
analysis of exfoliated and aspirated cells. E.g. pap smear

























