Pathology: Cellular Injury Flashcards
What is hypertrophy?
increased size of the cells (increased structural proteins and organelles)
What is hyperplasia?
Controlled proliferation of stem cells. Increased number of cells, can lead to dysplasia and cancer
What is atrophy?
Decrease the size and number of cells- destruction of cytoskeleton via ubiquitin-proteasome pathway. Autophagy and apoptosis. Caused by not using, denervation, lack of blood supply, lack of hormone, poor nutrition
Metaplasia
Reprogramming the stem cells to adapt to an insult
Dysplasia
Disordered, precancerous stem cell growth. Pleomorphism, nuclear changes,
Apoptosis
ATP programmed cell death. Intrinsic and extrinsic pathways. Eosinophilic cytoplasm and basophilic nucleus. pyknosis
Intrinsic apoptosis pathway (mitochondrial pathway)
tissue remodeling following embryogenesis- decreased IL2BAK and BAX, cytochrome C released from mitochondrial membrane, then activates caspases. Bcl2 keeps mito membrane impermeable (tumorigenesis)
Extrinsic pathway (death receptor pathway)
- Ligand receptor (Fas and TNF)
2. Immune cell (cytotoxic T cell)
Necrosis
enzymatic damage b/c of injury (inflammatory)
- Coagulative
- Liquefactive
- Caseous
- Fat
- Fibrinoid
- Gangrenous
What are Granulomas?
macrophages with pink cytoplasm with surrounding multinucleated giant cells and lymphocytes. IFN-y and TNF-a
What are the two types of calcification?
Dystrophic: 2nd to necrosis/injury (normal calcium levels) LOCALIZED
Metastatic: because of high calcium, hyperPTH (abnormal Ca levels) WIDESPREAD
What is lipofuscin?
yellow-brown wear and tear pigment that you see in elderly autopsies, autophagocytosed organellar membranes
What are hemachromatosis, Wilson’s, acetaminophen OD, ROP and reperfusion injury all examples of?
Free radical injury- DNA damage, protein modification, lipid perioxidation. Can be from radiation, drug metabolism, heavy metals, inflam (NO), WBC oxidative burst. free radicals can be removed by catalase, antioxidants ACE, superoxide dismutase, glutathione peroxidase
Scar formation?
nonregenerated cells replaced by connective tissue, 70-80% tensile strength by 3 months
What are keloid vs hypertrophic scars?
keloid are type 1 and 2 collagen, disorganized, go beyond the wound, upper extrem and face. Hypertrophic is type 3 collagen, organized strands parallel, stays in confines of original wound.