Cellular Death

Necrosis: cell death in an organ or tissue that is still part of a living person.

Liquefactive:	Such as the liquid exudates from the center of an abscess. – some cells catalogic enzymes still there, swollen pussy, draining
Coagulative:	Gray, firm mass– tissue hardens withers grey
Caseous	a form of coagulative necrosis with a “distinctive cheese-like center”. Cheesy material from fat-like infiltrate. Fat found in the breast pancre abd structures, spec cell dissolution caused by lipase
Gangrene:	A considerable amount of tissue death (necrosis).
Dry gangrene:	A form of coagulation necrosis usually from an interference of arterial blood flow.
Wet Gangrene:	Dry can be converted to wet. Wet is an interference of venous return and is a form of liquefactive necrosis. – venous
Gas Gangrene:	Special type of gangrene that results form infection of already devitalized tissues or from Clostridium bacterium. -an aerobic bacteria clostridia perfringens
Apoptosis :	“Cell suicide” eliminating cells that are worn out, in excess, have developed improperly or have genetic damage. – cell suicide

Apoptotic Cell Removal:

Shrinking of the cell à Condensing and fragmenting of chromatin à separation of nuclear fragments and cytoplasmic organelles into apoptotic bodies à engulfment of apoptotic fragments by phagocytic cells.

It is induced by tightly regulated intracellular program in which cells destine-to-die activate enzymes that degrade the cell zone nuclear DNA and cytoplasmic proteins. The cells plasma membrane remains intact but its structure is altered in such a way that the apoptotic cell becomes an avid target for phagocytosis.  The dead cell is rapidly cleared before its contents leaked out, therefore cell death by this pathway does not elicit an inflammatory response. It is a normal process.

 Examples of apoptosis

• Separation of webbed fingers and toes in the embryo
• Development of neural connections
• Removal of cells from intestinal villa
• Removal of senescent blood vessels. 

 

Brain Death General Criteria

Absence of breathing and movement

Absence of cranial nerve reflexes

Iunresponsiveness and unreceptivenes to any level of painful stimuli

Absent cerebral blood flow

Flat EEG - electroencephalogram

Tests must be done with patient at body less than 90 F

No CNS depressants