1. Efferent Peripheral Nervous Divisions cont.
Autonomic Motor - innervates cardiac muscle, smooth muscle, endocrine tissue and adipocytes
Somatic Motor - innervates skeletal striated muscle
Neurotransmitters and receptors

2. Human Physiology, 6th ed., Fox, SI; WC Brown, Fig.9.9
ACh neurotransmitter for all preganglionic fibers of both
ACh is neurotransmitter for postganglionic of parasympathetic
NE is neurotransmitter for postganglionic of sympathetic
Human Physiology, 6th ed., Fox, SI; WC Brown, Fig.9.9

3. Somatic Motor
Acetylcholine (ACh) acts on muscle nicotinic ACh receptors
Excitatory, causes muscle contraction

4. Somatic Motor Nervous System
Cell bodies in CNS
Send single axons to skeletal muscles
Excitatory, causes muscle contraction
Acetylcholine (ACh) acts on nicotinic ACh receptors

5. Muscles are innervated by nerves that originate in the brainstem or spinal cord and end at the neuromuscular junction with typically one junction per muscle fiber.
ACh (acetylcholine) is the neurotransmitter at all neuromuscular junctions. Not shown is how ACh is rapidly removed following release; otherwise, the action potentials would not cease causing continual contraction. Many drugs, including nerve gases, work at these locations by either blocking the neurotransmitter receptors or inhibiting the removal of the neurotransmitter.

7. Motor efferent pathways