Cholinergic Receptors

Question 1

What are the 2 types of ACh receptors?

Answer 1

Muscarinic receptors, Nicotinic receptors

Question 2

What are the two main functions of Nicotine and Muscarine as cholinergic compounds in the body

Answer 2

1. Produce actions that mimic those seen when ACh binds to muscarinic receptors of the parasympathetic nervous system “parasympathomimetic.”
2. Produce actions that mimic those seen when ACh binds to nicotinic receptors of autonomic ganglia and skeletal muscle receptors

Question 3

Where are Muscarinic Receptors located (what effector organs?)

Answer 3

Heart, smooth muscle, brain, exocrine glands

Question 4

What are the two key actions at muscarinic receptor sites

Answer 4

1. Alters organ function by creating a positive stimulus

2. Also alters organ function by creating a negative stimulus

Question 5

Where are Nicotinic receptors located?

Answer 5

Ganglionic level of both parasympathetic and autonomic NS

Question 6

What is the role of the Nicotinic receptors located on the preganglionic neurons?

Answer 6

Pass Ach from the pre-ganglionic neurons to the post-ganglionec neurons

Question 7

T/F Nicotinic receptors have inhibitory capabilities

Answer 7

F - nicotinic receptors have no inhibitory capabilities they only relay the efferent messages sent from the CNS

Question 8

T/F Nicotinic receptors are found in places other than NS.

Answer 8

T-Nicotinic receptors are also found in the neuromuscular and other locations (NM and NN)

Question 9

What is the role of ACh at nicotinic receptors in the Somatic NS?

Answer 9

Binding of ACh causes depolarization of the nerve cell creating a POSITIVE STIMULUS (i.e.; skeletal muscle contraction). However!!! Prolonged binding of ACh causes muscle to STOP firing, and creates a NEGATIVE STIMULUS.