W2: Cell Senescence and Death

Question 1

Irreversible injury leads to cell death. two types

Answer 1

necrosis

apoptosis

Question 2

Apoptosis characters:

cells
active/passive
membrane integrity
inflammation

Answer 2

cells - single
active/passive - active
membrane integrity - kept
inflammation - little

Question 3

There are intrinsic and extrinsic pathways in __.

Answer 3

apoptosis

Question 4

Necrosis characters:

cells
active/passive
membrane integrity
inflammation

Answer 4

cells - many adjacent cells
active/passive - passive
membrane integrity - lost; release of cell contents
inflammation - strong

Question 5

intrinsic/extrinsic pathway is associated with Bcl-2 and cytochrome C.

Answer 5

intrinsic (apoptosis, mitochondrial)

Question 6

extrinsic pathway is also called mitochondrial pathway. T/F

Answer 6

F; extrinsic = death receptor mediated

Question 7

intrinsic/extrinsic pathway is associated with Fas and TNF receptor.

Answer 7

extrinsic (apoptosis, death receptor)

Question 8

Last step of apoptosis is __

Answer 8

phagocytosis

Question 9

How is apoptosis initiated?

Answer 9

Intrinsic pathway: Bcl2 family proteins are triggered, which leads to release of cytochrome c

Extrinsic pathway: receptor ligand binding triggers FADD

Ultimately both trigger caspase

Question 10

How can hypoxia lead to necrosis?

Answer 10

Hypoxia is lack of blood and oxygen supply to a tissue. This leads to decrease in ATP production in mitochondria, which leads to increased Ca++ level in the cell and trigger necrosis.

Question 11

What happens when ATP is depleted?

Answer 11

Ca++ level inside the cell increases.

Question 12

What happens when intracellular calcium is elevated?

Answer 12

It triggers necrosis.

ATP, calcium, necrosis

Question 13

Molecules secreted by senescent cells (cytokines, chemokines, proteases and growth factors) are called ___.

Answer 13

SASP (Senescence Associated Secretory Phenotype)