Irreversible cellular injury

Question 1

Define Autolysis

Answer 1

The digestion of the body’s own cells using digestive enzymes such as lysosomes.

Question 2

Define Necrosis

Answer 2

Necrosis is the death of body tissue. It occurs when too little blood flows to the tissue. This can be from injury, radiation, or chemicals. Necrosis cannot be reversed.

Necrosis happen due to digestive enzyme or denaturation of protein

Question 3

Outline the process of necrosis

Answer 3

Physical trauma and heat can initiate necrosis

The first of these two pathways initially involves oncosis, where swelling of the cells occurs.[15] Affected cells then proceed to blebbing, and this is followed by karyopicnosis. (where nucleus shrinks and chromatin condenses),

After that karyorrhexis develops. This process is characterised by rupture of nuclear membrane and fragmentation of the nucleus. Nucleus is decomposed into small granules.

step of this pathway cell nuclei are dissolved into the cytoplasm, which is referred to as karyolysis.[15]

The second pathway is a secondary form of necrosis that is shown to occur after apoptosis and budding.[15] In these cellular changes of necrosis, the nucleus breaks into fragments (known as karyorrhexis).[15]

Autolysis

Question 4

What are the different types of necrosis

Answer 4

Coagulative necrosis= this is the preservation of dead tissue for a couple of days because they do not immediately undergo autolysis. In the early stages they appear pale, firm and slightly swollen. After they progress they become yellow, softer and shrunken. This is associated with typhoid fever.

liquefactive necrosis (or colliquative necrosis) is a type of necrosis which results in a transformation of the tissue into a liquid viscous mass. Often it is associated with focal bacterial or fungal infections, and can also manifest as one of the symptoms of an internal chemical burn.

Gangrene necrosis this is when the tissue has been in contact with the outer environment it is characterized by a black colour. Found in the low extremities, uterus, lungs, there are 3 main types of gangrene which are dry, wet and gas.

Infarction= tissue death due to inadequate blood supply

Fat necrosis= this occurs in areas where there is a lot of adipose tissue. This happens due to a physical trauma namely the breast
Grossly, fat necrosis appears as firm, yellow-white deposits in peripancreatic and mesenteric adipose tissue. Histologically, necrotic fat cells are distinguishable as pale outlines, and their cytoplasm is filled with an amorphous-appearing, faintly basophilic material (soap).

Caseous necrosis This is when the tissue turn to cheese (yellow) form. this happens due to TB when the lymph node form caseous??

Fibrinoid necrosis deposition of fibrin-like material, which has the staining properties of fibrin. It is encountered in various examples of immunologic tissue injury, arterioles in hypertension, peptic ulcer etc. Histologically, fibrinoid necrosis is identified by brightly eosinophilic, hyaline like deposition in the vessel’s wall or on the luminal surface of a peptic ulcer.

Question 5

Define Apoptosis

Answer 5

This is programmed cell death

Question 6

Describe the process of Apoptosis

Answer 6

1. Cell shrinkage;
2. Chromatin condensation;
3. Formation of cytoplasmic blebs and apoptotic bodies; 4. Phagocytosis of apoptotic cells or bodies.

Histologically by using the Hand E stain as the cytoplasm is eosinophillic it will stain pink. it will appear round and oval in structure

Question 7

What are the different types of Gangrene

Answer 7

Dry and wet
Dry= mainly limb, artries, shrunken and black, limited blood supply, bacteria fail too survive, prognosis of pt better

Wet= mainly in bowels, veins, moist, soft swollen and rotten

Question 8

What are the 2 types of death

Answer 8

Clinical death= cessation of blood circulation and breathing, the two necessary criteria to sustain human and many other organisms’ lives. It occurs when the heart stops beating in a regular rhythm, a condition called cardiac arrest. The term is also sometimes used in resuscitation research. This is reversible

Biological death= cessation of blood circulation and breathing, the two necessary criteria to sustain human and many other organisms’ lives. It occurs when the heart stops beating in a regular rhythm, a condition called cardiac arrest. The term is also sometimes used in resuscitation research. Unreversible

Question 9

List what happens after biological death

Answer 9

Coolness of skin

numbness

drying

The blood redistributes towards gravity

patches

putrification of corpse