Cell Injury Part 3 Flashcards
Describe the morphology of apoptosis
- Cell shrinkage with separation from adjacent cells
- Nuclear chromatin condensation
- Apoptotic bodies
- Phagocytoses of apoptotic bodies by macrophages.
Discuss the intrinsic pathway of apoptosis (initiation phase)
- Anti-apoptotic cytoplasmic protein Bcl-2 maintain integrity of mitochondrial membrane
- Loss of growth factors and the proteins that sense this inhibit these proteins
- Causes cytochrome c to get into cytoplasm.
- Activates caspases
Explain the extrinsic pathway (initiation phase)
Fas Ligand binds to Fas receptor
Discuss the execution phase
Initiator caspases lead to activation of a executioner caspases that cleave DNA, nuclear proteins and cytoskeletal proteins
Describe the Cell removal phase.
Changes in CM and apoptotic bodies promote their phagocytosis.
Discuss dust as an exogenous pigment
Inhaled carbon; Anthracosis. Causes black discoloration and inflammation. Dust particles found in macrophages.
Discuss lipofuscin as an endogenous pigment
From aging; Sign of free radical injury and lipid peroxidation. Histologically light brown to yellowish
Discuss hemosiderin as an endogenous pigment
Derived from iron in hemoglobin. Caused by prolonged congestion, hemorrhage, and hemolysis
Discuss Bilirubin as an endogenous pigment
Major pigment in bile
Explain Dystrophic calcification
Calcium salt deposit in areas of injury; Blood calcium is normal. Appears basophilic
Explain Metastatic calcification
Calcium deposition in uninjured tissues; Associated with Hypercalcemia
What are the 4 causes of hypercalcemia?
- Increased PTH
- Destruction of bone
- Vitamin D related disorders
- Renal failure
What are the common sites of calcium deposition.
- Gastric mucosa
- Kidneys
- Lungs
- Systemic arteries
- Pulmonary veins
