ANS receptors

Question 1

Name 4 adrenoreceptors and state their function

Answer 1

a1 - increase IP3 and DAG releasing Ca, vasoconstriction of SM (not GI)

a2 - decrease adenyl cyclase and cAMP, presynaptic inhibition, contraction of VSM

B1 - increase adenyl cyclase, cAMP, PKA, Ca; cardiac HR and force of contraction increases

B2 - relaxation of SM

Question 2

Which division of the ANS do adrenoreceptors belong to?

Answer 2

Sympathetic

Question 3

Name to 2 different parasympathetic cholinergic receptors, and the type of receptor

Answer 3

Nicotinic - ligand gated ion channel

Muscarinic - G-protein coupled

Question 4

What does stimulation of a nicotinic receptor cause?

Answer 4

Increased permeability to Na and K

Question 5

What are the 3 subtypes of nicotinic receptors?

Answer 5

1. Skeletal
2. Ganglionic
3. Neural

Question 6

What are the 5 subtypes of muscarinic receptors?

Answer 6

• M1 - ganglia, CNS, gastric parietal cells; decrease K conductance
• M2 - heart and brainstem; inhibits adenyl cyclase, opens K channels and inhibits Ca channels
• M3 - SM, glandular tissues, cerebral cortex; relaxes VSM
• M4 - CNS; inhibits adenyl cyclase
• M5 - CNS; activates PLC