Cellular communication 8

Question 1

Which statement is NOT a feature of cell death by apoptosis?
a. apoptosis is genetically programmed
b. cells shrink during apoptosis
c. plasma membranes are intact during apoptosis
d. inflammation in surrounding tissue is common in apoptosis

Answer 1

d. inflammation in surrounding tissue is common in apoptosis

Question 2

_________is cell death by uncontrolled chaotic cellular events in response to cell injury

Answer 2

Necrosis

Question 3

Describe what happens during necrosis.

Answer 3

cells swell
DNA condenses and dissolves
plasma membranes are disrupted
cell contents are dissolved and leak out
adjacent tissues undergo inflammatory processes

Question 4

_____________ is characterized by genetically controlled and programmed cell death pathways

Answer 4

Apoptosis

Question 5

Describe what happens during apoptosis.

Answer 5

cells shrink
nucleus is systematically fragmented
plasma membranes are intact
cellular contents are usually intact
cell components are packaged into “bite-sized” apoptosomes & digested by phagocytosis, all without causing inflammation in surrounding tissues

Question 6

Death by apoptosis is a ______ physiologic phenomenon that eliminates cells that are no longer needed and maintains a steady number of various cell populations.

Answer 6

normal

Question 7

Almost all _____________ drugs cause apoptosis of _______ cells

Answer 7

chemotherapeutic drugs; cancer

Question 8

What are the two pathways that initiate apoptosis?

Answer 8

the intrinsic (or mitochondrial pathway)
extrinsic (death receptor-initiated) pathway

Question 9

The intrinsic and extrinsic pathways then converge on the

Answer 9

effector (executioner) pathway

Question 10

What are the three forms of cell death?

Answer 10

necrosis
apoptosis
autophagic cell death

Question 11

The main biochemical features of apoptosis are:

Answer 11

activation of caspases
membrane alterations & recognition by phagocytes
DNA, protein, lipid, and cell components break down into “bite-sized” fragments

Question 12

Two families of proteins are key regulators of apoptosis:

Answer 12

caspases & B-cell lymphoma proteins

Question 13

Which protein keeps mitochondrial Bax/Bak pores in check in healthy cells?

Answer 13

Bcl-2

Question 14

What type of cell digests apoptotic bodies?

Answer 14

phagocytes

Question 15

What leads to the intrinsic (mitochondrial) pathway?

Answer 15

damage to the mitochondria by reactive oxygen species or increases in intracellular Ca2+ result in the opening of large pores

Question 16

The apoptosome activates ______________ and commits the cell to apoptosis in the intrinsic pathway

Answer 16

caspase-9

Question 17

The extrinsic pathway is triggered by

Answer 17

extracellular signals bind to transmembrane death receptor

Question 18

The ____________ converges from the extrinsic pathway with caspase-9 from the intrinsic pathway to converge on the executioner pathway

Answer 18

Caspase-8

Question 19

Executioner caspases are

Answer 19

3 & 7

Question 20

In the presynaptic nerve terminal, opioid-activated G protein By subunits block:
a. voltage-gated Ca2+ channels
b. voltage-gated Na+ channels
c. voltage-gated K+ channels
d. voltage-gated Cl- channels

Answer 20

a. voltage-gated Ca2+ channels

Question 21

B1-adrenoreceptor stimulation of cardiac myocytes produces

Answer 21

positive chronotropic, dromotropic (conduction velocity), inotropic, and lusitropic (relaxation) effects by cAMP-mediated signal transduction pathways

Question 22

Many signals at endothelial cells lead to the production of

Answer 22

nitric oxide (NO) and vasodilation

Question 23

Opioids exert _______________________ responses in neurons through G protein-coupled receptor signal transduction pathways

Answer 23

both presynaptic and postsynaptic inhibitory

Question 24

________________ are the sole known enzymes for terminating cyclic nucleotide signals

Answer 24

Cyclic nucleotide phosphodiesterases (PDE)

Question 25

_________________ plays a key role in water regulation at the terminal nephron

Answer 25

Vasopressin, also known as arginine vasopressin (AVP) and antidiuretic hormone (ADH)

Question 26

Opioids exert __________________________ responses in neurons

Answer 26

both presynaptic and postsynaptic inhibitory

Question 27

In presynaptic neurons, GBy subunits block

Answer 27

voltage-gated Ca2+ channels

Question 28

Vasopressin plays a key role in BP control at two different tissues:

Answer 28

blood vessels & nephrons in the kidney

Question 29

______________ are the sole known enzyme for terminating cyclic nucleotide signals.

Answer 29

Cyclic nucleotide phosphodiesterases

Question 30

Inhibition of SERCA2 is relieved by phosphorylation of:

Answer 30

phospholamban

Question 31

Endothelial nitric oxide synthase (eNOS) is activated by:

Answer 31

Ca2+/CaM complex

Question 32

Water reabsorption in principal cells of the collecting duct is increased by the insertion of what protein into the apical membrane?

Answer 32

Aquaporin 2 (APQ2)