Receptors

Question 0

a1 receptor

Answer 0

Sympathetic, Gq
Increases vascular smooth muscle contraction, intestinal and sphincter muscle contration, pupillary dilator muscle contraction.

Question 1

What is the difference between nicotinic and muscarinic receptors?

Answer 1

Nicotinic: ACh receptors, ligand gated Na+/K+ channels, found in autonomic ganglia (first order) and somatic neuromuscular junction/skeletal muscle.
Muscarinic: ACh receptors, GPCRs, parasympathetic and sweat gland 2nd order neurons.

Question 2

a2 receptor

Answer 2

Sympathetic, Gi

Decreases sympathetic outflow, decreases insulin release and lipolysis, increases platelet aggregation

Question 3

b1 receptor

Answer 3

Sympathetic, Gs

Increases HR and contractility, increases renin, increases lipolysis

Question 4

b2 receptor

Answer 4

Sympathetic Gs
Vasodilation, bronchodilation, increases HR and contractility, increases lipolysis and insulin release, decreases uterine tone, ciliary muscle relaxation, increase aqueous humor production

Question 5

M1 receptor

Answer 5

Parasympathetic Gq

CNS and enteric NS

Question 6

M2 receptor

Answer 6

Parasympathetic, Gi

Decreases HR and atrial contractility

Question 7

M3 receptor

Answer 7

Parasympathetic, Gq
Exocrine gland secretions, peristalsis, bladder contraction, bronchoconstriction, pupillary sphincter muscle and ciliary muscle contraction

Question 8

D1 receptor

Answer 8

Dopamine receptor, Gs

Relaxes renal vascular smooth muscle

Question 9

D2 receptor

Answer 9

Dopamine receptor, Gi

Modulates neurotransmitter release

Question 10

H1 receptor

Answer 10

Histamine receptor, Gq

Nasal and bronchial mucus production, increased vascular permiability, bronchiole constriction, pruritis, pain

Question 11

H2 receptor

Answer 11

Histamine receptor, Gs

Gastric acid secretion

Question 12

V1 receptor

Answer 12

Vasopressin receptor, Gq

Vascular smooth muscle contraction

Question 13

V2 receptor

Answer 13

Vasopressin receptor, Gs

Found in kidneys, increases water permeability and readsorption

Question 14

Gq receptors and mechanism

Answer 14

a1, M1, M3, H1, V1 (HAVMM)

Phospholipase C, IP3 and DAG, PKC and increased Ca –> smooth muscle contraction

Question 15

Gs receptors and mechanism

Answer 15

B1, B2, D1, H2, V2

Adenylyl cyclase –> cAMP –> PKA –> Ca++ in heart, MLCK in smooth muscle

Question 16

Gi receptors and mechanism

Answer 16

M2, A2, D2 (MAD2)

Inhibits: Adenylyl cyclase –> cAMP –> PKA –> Ca++ in heart, MLCK in smooth muscle