Which receptors are associated with the parasympathetic nervous system?

The receptors associated with the parasympathetic nervous system are cholinergic receptors. These receptors respond primarily to the neurotransmitter acetylcholine, which is released by the parasympathetic fibers. There are two main types of cholinergic receptors: nicotinic and muscarinic receptors. Nicotinic receptors are found at the neuromuscular junction and in the autonomic ganglia, while muscarinic receptors are located on organs and tissues innervated by the parasympathetic nervous system, such as the heart, smooth muscles, and glands.

Through these interactions, cholinergic receptors facilitate the various body functions managed by the parasympathetic system, such as decreasing heart rate, increasing digestion, and promoting energy conservation and recovery during rest. This is contrasted with adrenergic receptors, which are involved with the sympathetic nervous system and respond to norepinephrine and epinephrine, typically contributing to the body's 'fight or flight' responses.