Cellular adaptation and Neoplasia and other terms

Metaplasia

the conversion from one adult cell type to another adult cell type, benign change

hyperplasia

an increase in the number of cells of an organ or tissue

causes of hyperplasia

occurs due to cell division

2 different stimuli associated with hyperplasia

Physiologic- natural

Non-physiologic- unnatural, ex: tumor

hypertrophy

increase in the size of an organ due to an increase in cell size rather than division

causes of hypertrophy

caused by increased functional demands (needs more cells)

may be either increased rate of protein synthesis or decreased rate of protein degradation

may be either physiologic or pathologic

atrophy

decrease in size of body part brought about by shrinkage in size of cells

causes of atrophy

disuse, decreased nutrition, ischemia

dysplasia

deranged cell growth or development of a specific tissue that results in cells with variations in size, shape, and appearance

other dysplasia facts

cells are arranged in a disorganized manner

may be reversible if the factor causing dysplasia does not exist in the body anymore

cell injury

extent and duration of cell injury will determine if reversible or if death of cell/organism will occur

reversible cell injury

cellular swelling, fatty changes, intracellular accumulations

cellular swelling

accumulation of water within the cell

fatty changes

usually represents severe injury

occurs because normal cells are presented with increased fat load or because injured cells are unable to metabolize fat properly

what is particular susceptible to fatty changes?

the liver

intracellular accumulations

abnormal accumulation of lipids, proteins, pigments, and carbs, in storage of cell

accumulation disorders are associated with many genetic diseases

hypoxic injury

deprives the cell of oxygen, causing a “power failure”

other hypoxic injury facts

one of the most common causes of tissue injury

produces irreversible cell damage when prolonged

if O2 is restored, cell damage is reversible

if O2 is not restores, cell damage is irreversible

irreversible cell injury and death

necrosis and gangrene

necrosis- marked changes of cell appearance

liquefaction, coagulation, caseous (cheese-like appearance)

gangrene

decay or death of an organ or tissue caused by lack of blood supply

gangrene results from

infectious or inflammatory process, injury, or degenerative changes

cause of dry gangrene

occurs when blood supply to tissue is cut off

dry gangrene

the part becomes dry and shrinks

confined to extremities

dark brown or black

slow spread

can become wet gangrene if tissue undergoes bacterial invasion

cause of wet gangrene

primarily due to interference with venous return

wet gangrene

associated with bacterial invasion

area turns cold and is swollen

skin is moist and black

rapid tissue damage spread

may affect internal organs or extremities

can lead to necrosis

cause of gas gangrene

due to infection of tissues by one of several bacteria

gas gangrene

bubbles of gas form in muscle

anaerobic bacteria produce toxin that cause shock, hemolysis and muscle cell death

serious and potentially fatal

treatment may include hyperbaric medicine

neoplasms

new formation

neoplasm facts

does not obey laws of normal tissue growth

tends to increase in size and survive at expense of rest of body

tumor

neoplasm classification

benign or malignant

manner and rate of growth

tendency to recur or metastasize

benign neoplasm

well-differentiated mature tissue types

slow expansive growth

well-defined borders

neoplasms malignant

poorly differentiated tissue types

rapid growth

invades surrounding tissue

causes thrombosis

metastasis

rate of both normal and abnormal tumor growth

cause of metastasis

spread occurs when malignant tumor invades vascular or lymphatic channels

stage I cancer

confined to organ

stage II cancer

spread is outside of organ, still within capsule

stage III cancer

spread outside of organ and capsule

stage IV cancer

distant metastasis

carcinogenesis

the process by which normal cells transform into cancer cells

apical

relating to the apex

ectasia

expansion of a hollow or tubular organ

costal

relating to the ribs

subcostal

beneath a rib

homeostasis

tendency to maintain stability or equilibrium

hyperbaric medicine

medical treatment that involves increasing barometric pressure above ambient levels

ischemia

deficient blood supply to a part of the body

para-

alongside of or near

pathogenesis

biological mechanism by which a disease develops and progresses within the body

phagocytosis

ingestion of bacteria or other material by phagocytes

parasternal

situated beside the sternum

Trendelenburg position

supine with body angled so that feet are higher than the head

reverse Trendelenburg position

supine with body angled so that the head is higher than the feet