Please Fill in the blank (#45, 46) or circle the correct answer (#47-50). Vagal
ID: 146142 • Letter: P
Question
Please Fill in the blank (#45, 46) or circle the correct answer (#47-50).
Vagal nerve stimulation slows the heart rate: How does this occur?
45. Vagal stimulation results in the release of _______________________,
46. The released neurotransmitter binds to the _________________ receptor subtype .
47-50 (circle correct answer) This receptor activation results in the dissociation of the G protein subunits. The Gai subunit (stimulates/inhibits) adenylyl cyclase. The Gbg subunit (activates/inhibits) G-protein coupled inward rectifying potassium channels (GIRKs). This results in K+ (inflow/outflow) which causes (depolarization/hyperpolarization), thus decreasing the heart rate.
Explanation / Answer
Answer :45 Vagal Stimulation results in the release of Ach I.e. Acetylcholine.
Answer 46 : binds to the M2 muscarinic receptor.
Answer 47 : Gai subunit inhibits adenylyl cyclase.
Answer 48: Gbg subunit activates G-protein coupled inward rectifying potassium channels.
Answer 49-50: This results in K+ outflow which causes hyperpolarisation, thus decreasing the heart rate.