Question

M1 receptors are present on which of the following?

a. Heart, postganglionic parasympathetic nerves
b. Parasympathetic ganglia, nasal submucosal glands
c. Airway smooth muscle, submucosal glands
d. Postganglionic cholinergic nerves, possible effect on CNS

Answer 1

M1 receptors are present on the heart, postganglionic parasympathetic nerves, airway smooth muscle, and submucosal glands.

Step-by-step explanation:

M1 receptors are present on the heart, postganglionic parasympathetic nerves, airway smooth muscle, and submucosal glands. These receptors are part of the muscarinic receptor family and are activated by acetylcholine (ACh), a neurotransmitter released by parasympathetic nerves. The activation of M1 receptors can have various effects on these targets, such as slowing down heart rate and constricting airway smooth muscles.