Cell Injury, Adaptations and Death Flashcards
What is hyperplasia
increase in cell NUMBER; occurs in labile and stable cells ; physiologic: female breast at puberty and in pregnancy, after liver partial resection; pathologic: hormonal imbalance stimulate endometrial hyperplasia increase risk for cancer!! , BPH-formation of nodules in prostate gland resulting in urinary obstruction, (not increased risk for cancer)
What is hypertrophy
increase in SIZE of cells; physiologic: increased skeletal muscle in weight living, uterus in pregnancy; pathologic: cardiac muscle hypertrophy (enlarged nuclei and myofiber width)
What is atrophy
decrease in size of cell due to loss of cell substance; decreased fxn but not death; physiologic: loss of hormonal stimulation (endometrium at menopause), pathologic: decreased functional demand (trauma to peripheral nerve, broken arm)
What is Metaplasia
one adult cell type replaced by another that is better able to handle the stress examples: chronic smokers-cells are reprogrammed, from ciliated columnar epithelium to squamous epithelium, acid reflux/Barett Esophagus: squamous epithelium becomes gastric/intestinal type, bone formation in soft tissue, columnar becomes squamous in cervical tissue increasing risk of HPV infeciton
What are characteristics of necrosis?
swelling; membrane blebs, breakdown of plasma membrane, organelles, leakage of contents, adjacent inflammation
What are characteristics of apoptosis?
condensation of chromatin, membrane blebs, cells shrink, cellular fragmentation, apoptotic bodies, INTACT plasma membrane, no adjacent inflammation
What are the 6 types of necrosis?
coagulative, liquefactive, caseous, fatty, gangrenous, fibrinoid
Coagulative necrosis is distinguished by:
results from hypoxic or anoxic injury due to ischemia, persistence of dead cells with intact outlines but loss of cellular details, injury denatures both cellular proteins and enzymes, occurs in ALL solid organs EXCEPT brain
Liquefactive necrosis is distinguished by:
complete digestion of dead cells, commonly seen with bacterial/fungal infections, PUS, ABCESS, usually happens in brain infarcts, acute polynephritis, no residual tissue is preserved
Caseous necrosis is distinguished by:
resembles cheese, fragmented and coagulated cells with loss of tissue architecture, surrounded by a border of inflammatory cells (granuloma), center=necrosis
Fat necrosis is distinguished by:
typically seen in pancreas, release of lipases and triglyceries, liquifies fat, smudgy purple areas in microscope-fatty necrosis
intracellular responses to injury
decreased ATP, increased ROS, damage to lipids, proteins, loss of cellular components, activation of pro-apoptotic proteins, influx of Ca2+, decreased glycogen, decreased pH, climbing of nuclear chromatin,
Pathologic calcification vs Metastatic calcification
dystrophic: damaged tissues with normal serum calcium (aortic valves in elderly, lymph nodes with old TB)-get white gritty deposits; metastatic: normal tissues with hypercalcemia, increased PTH, destruction of bone, Vit D intoxication, renal failure, in lung, kidney, gastric mucosa
Cellular aging is defined by:
DNA damage increases with age, decreased cellular replication, progressive shorting of telomeres, lack of telomerase (which usually maintains telomerase length), defective protein homeostasis
What are the four kinds of cellular adaptations?
Hyperplasia, hypertrophy, atrophy, metaplasia
