Homeostasis

Question 1

What can lack of apoptosis in humans lead to

Answer 1

Webbed fingers called syndactyly

Question 2

What is the importance of apoptosis

Answer 2

-normal cell turn over
-tissue homeostasis
- induction and maintenance of immune tolerance
- development of the nervous system

Question 3

What is necrosis

Answer 3

It’s the pathological cell death which occurs when cells are exposed to a serious physical or chemical insult

Question 4

What is apoptosis

Answer 4

It’s the physiological cell death which unwanted or useless cells are eliminated during development and other normal biological processes

Question 5

Name a morphological feature difference between the two

Answer 5

Necrotic cells- volume enlargement
-Swelling of cytoplasm and mitochondria
- loss of membrane integrity

Apoptosis cells- volume reduction
-shrinking of cytoplasm
-no loss of membrane integrity

Question 6

Biochemical feature difference between the two

Answer 6

Necrotic cells- loss of regulation of ion homeostasis
-no energy requirement

Apotic cells- tightly regulated process
- energy dependent

Question 7

Psychological difference between the two

Answer 7

Necrosis
-affects groups of contagious cells
-evoked by non physiological disturbances
- significant inflammatory response

Apoptosis
-affects single cells or small clusters of cells
-induced by physiological stimuli
-no inflammatory respnse

Question 8

What are the two pathways for apoptosis

Answer 8

-extrinsic pathway- (death receptor mediated events)
- instrinsic psthway- (mitochondria- mediated events)

Question 9

Necrosis summary

Answer 9

-associated with the loss of control of ionic balance
-uptake of water
-swelling
-cellular lysis
-the lysis releases intracellular constituents attracting immune cells and leading to an inflammatory response

Question 10

Name a stress for cells

Answer 10

Oxidative