Pathophysiology Chapter 3: Cellular Injury, adaptations, and Maladaptive Changes

atrophy

A wasting or diminution of size,often accompanied by a decrease infunction, of a cell, tissue, or organ.

hypertrophy

The enlargement orovergrowth of an organ that is due to anincrease in the size of its cells ratherthan the number of its cells.

hyperplasia

An abnormal multiplicationor increase in the number of normal cellsof a body part.

metaplasia

Change in type of adultcells in a tissue to a form that is notnormal for that tissue.

dysplasia

The alteration in size, shape,and organization of adult cell types.

apoptosis

A mechanism ofprogrammed cell death, marked byshrinkage of the cell, condensation ofchromatin, formation of cytoplasmicblebs, and fragmentation of the cell intomembrane-bound bodies eliminated byphagocytosis

cellular homeostasis

maintaining a balance of several factors that make a cell healthy

infarction

Necrosis or death of tissues due to local ischemia resulting from obstruction of blood flow. (heart attack)

necrosis

Localized tissue death that occurs in groups of cells or part of a structure or an organ in response to disease or injury.

1. change structure and or function (adaptation)
2. cell death

what are the two cell responses to injury

size, number, and type

cells can adapt by changing in...

atrophy

decrease in cell size

disuse, loss of nerve supply, decreased blood supply, malnutrition, and loss of hormonal stimulation

what can cause atrophy?

hypertrophy

increase in individual cell size

usually a response to a specific organ to an increased demand for work

what can cause hypertrophy?

hyperplasia

increase in number of cells

physiological hyperplasia

occurs when there is hormonal stimulation (puberty and pregnancy)

compensatory hyperplasia

occurs in organs that are capable of regenerating lost tissues (ex: when part of the liver is destroyed)

pathologic hyperplasia

seen in abnormal stimulation of organ cells that are capable of regeneration (goiter and gingivitis are examples)

metaplasia

reversible change in one type of adult cell is replaced by another type to suite the hostile environment better

dysplasia

the appearance of cells that have undergone some atypical changes

no bc it serves no specific functions

is dysplasia a true adaptive process?

epithelial cells

what type of cells are common sites for dysplastic changes?

Intracellular accumulations

the buildup of substances that cells cannot immediately use or eliminate

normal body substances, abnormal endogenous products, and exogenous products

what are the different types of intracellular buildup?

lipids, proteins, carbohydrates, melanin, and bilirubin

what are examples of build up of normal body substances?

abnormal proteins or metabolic enzymes from genetic mutations

what are examples of build up of abnormal endogenous products?

environmental agents and pigments like lead and radiation

what are examples of build up of exogenous products?

pathologic calcification

involves the abnormal tissue deposition of calcium salts, together with smaller amounts of iron, magnesium, and other minerals

dystrophic calcification

pathological calcification in dead or dying tissue

metastatic calcification

pathological tissue occurring in normal living tissue

hyperparathyroidism, cancer in the bone, and Vitamin D intoxication

examples of metastatic calcification...

physical agents, chemical agents, and microorganisms, hypoxia, genetic defects, nutritional imbalances, and immunological reaction

common causes of cellular injury

hypoxia

most common cause of cellular injury

inadequate oxygen in the blood or decreased tissue perfusion

hypoxia

apoptosis and necrosis

what are the two types of cell death?

in programmed cell death: apoptosis

when are dead cells replenished by new cells?

in cell death caused by external injury/pathologic: necrosis

when are dead cells not replaced by new ones?

liquefaction

some cells die, but their enzymes are not destroyed

coagulation

acidosis causes cell destruction

casesous

conversion to a cheese like material (ex: TB)

liquefaction, coagulation, infarction, and caseous

what are the four types of necrosis

dry, wet, and gas

what are the three types of gangrene?

dry gangrene

arterial interruption, usually confined to theextremities spreads slowly, area is dry and wrinkled,black or brown, line of demarcation, usually not fatal

wet gangrene

venous interruption, usually internal, spreadsquickly, area is moist, cold, swollen, and undertension, bacterial invasion is common, potentiallyfatal

gas gangrene

infection of devitalized tissues, clostridium, anaerobic, common in injuries where dirt and debris are imbedded, bubbles form, potentially fatal

cell aging

due to progressive decline in proliferative and reparative capacity of cells combined with exposure to the environment