Neurotransmitter Receptor Types and Effects
Acetylcholine (ACh)
Cholinergic neurotransmitter; excites postganglionic neurons and parasympathetic target organs
Nicotinic
Type of acetylcholine medullary cells, and neuromuscular receptor found in all postganglionic neurons,
adrenal junctions of skeletal muscle; binding leads to excitation
Muscarinic
Type of acetylcholine receptor found in all parasympathetic target organs; binding leads to excitation in
most cases and inhibition of cardiac muscle
Norepinephrine (NE)
Adrenergic neurotransmitter B1; increases heart rate and force of contraction, stimulates kidneys to
release renin
B2- Receptor type
-Lungs and most other sympathetic target organs; abundant on blood vessels serving the heart, liver, and
skeletal muscle
-Effects mostly inhibitory; dilates blood vessels and bronchioles; relaxes smooth muscle walls of digestive
and urinary visceral organs; relaxes uterus
B3 Receptor type
-Adipose tissue
Acetylcholine (ACh)
Cholinergic neurotransmitter; excites postganglionic neurons and parasympathetic target organs
Nicotinic
Type of acetylcholine medullary cells, and neuromuscular receptor found in all postganglionic neurons,
adrenal junctions of skeletal muscle; binding leads to excitation
Muscarinic
Type of acetylcholine receptor found in all parasympathetic target organs; binding leads to excitation in
most cases and inhibition of cardiac muscle
Norepinephrine (NE)
Adrenergic neurotransmitter B1; increases heart rate and force of contraction, stimulates kidneys to
release renin
B2- Receptor type
-Lungs and most other sympathetic target organs; abundant on blood vessels serving the heart, liver, and
skeletal muscle
-Effects mostly inhibitory; dilates blood vessels and bronchioles; relaxes smooth muscle walls of digestive
and urinary visceral organs; relaxes uterus
B3 Receptor type
-Adipose tissue
