General Pathology Flashcards
Deeply eosinophilic cytoplasm, cell shrinkage and basophilia with membrane blebbing
Apoptosis
Look for nuclear fragmentation and formation of apoptotic bodies as well.
BAX and BAK are both what sort of proteins?
What about Bcl-2?
BAX and BAK are both pro-apoptotic from the mitochondria.
Bcl-2 is antiapoptotic and prevents cytochrome c release by binding to and inhibitin Apaf-1
Describe the intrinsic pathway of apoptosis.
Bcl-2 is inhibited leading to the release of BAX and BAK.
BAX and BAK act at the mitochondria to release cytochrome c. Cytochrome c carries out cytosolic caspaces that break down the cell.
Describe the extrinsic pathway of apoptosis
Ligand receptor interactions FasL binding to Fas (important in the thymus for negative selection)
and
Cytotoxic T cells releasing perforin and granzyme B
Coagulative necrosis
Ischemia and infarcts in most tissues except the brain.
Cell outlines are generally preserved by cytoplasm will bind to acidophilic dyes.
Liquefactive necrosis
Seen in bacterial abscesses and brain infarcts due to high fat content.
Done by neutrophils* releasing lysosomal enzymes into the tissue.
Caseous necrosis
Seen with tuberculosis and systemic fungi.
Macrophages wall of the infecting organism.
Fat necrosis
Enzymatic due to acute pancreatitis.
The damaged cells release lipase which leads to fatty acid break down in cell membranes.
Fibrinoid necrosis
Immune reactions in blood vessels.
The immune complexes bind fibrin within the vessels.
Gangrenous necrosis
Distal extremities after chronic ischemia.
When wet it is considered a super infection and is liquefactive.
What type of necrosis is seen in wet gangrene?
Liquefactive.
When dry it is considered coagulative (the go to)
Which area in the liver is most suceptible to ischemia?
Zone 3 as its furthest from the blood supply.
What is a red infarct?
Hemorrhaigic occuring in venous occlusion with multiple blood supplies.
Be careful with reprofusion as it can lead to a reprofusion injury when free radicles from the circulation are sent to the tissue
What is a pale infarct?
Pale infarcts are due to ischemia in organs tha thave only single ended blood supplies such as the heart, kidney, and spleen.
5 cardinal signs of an infection?
Redness Pain Swelling Heat Loss of function
Acute inflammation includes…
Neutrophils and eosinophils. IgM plays a role as well.
Chronic inflammation includes…
Mononucear cells and fibroblasts
You will find persistant destruction and repair cycles.
You see a neuron that has round cellular swelling, the nucleus has been displaced to the periphary and there is a ton of Nissl substance in the cytopasm… this is highly indicative of?
Highly indicative of a neuron that has undergone damage and is attempting to repair itself.
The cell body ramps up its protein production in an effort to repair its damaged axon.
Dystrophic calcium
Calcium deposition in abnormal tissues secondary to injury or necrosis.
Serum calcium levels will be normal and this is key.
Metastatic calcium
Widespread deposition of calcium in normal tissue secondary to hypercalcemia or high calcium-phosphate product.
Serum calcium levels will not be normal in these patients.
ICAM-1 and VCAM-1 are important for what cellular action?
These two are expressed on the vasculature and are important for the tight binding step during extravasation.
they bind onto integrins.
PECAM-1 is important for what cellular action?
The PECAMS bind eachother during extravasation and allow for diapedesis (WBC travels between the endothelial cells)
E selectin and P selectin as well as GlyCAM-1 are important for which cellular function?
These are cell surface molecules that interact with the selectins of WBC for margination and rolling durin leukocyte extravasation.
How long does it take until a scar has regained 70-80% of its tensile strength?
Three months.
Very little tensile strength will be regained after that time.
What does the tissue mediator PDGF do when involved in wound healing?
It is secreted by platelets and macrophages inducin vascular remodeling and smooth muscle cell migration.
Stimulates fibroblast growth for collagen synthesis.
What does the tissue factor FGF do when involved in wound healing?
FGF stimulates angiogenesis
What does the tissue factor EGF do when involved in wound healing?
EGF stimulates cell growth via tyrosine kinases