Transcript Somatic Motor Division 11/8/01

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
Human Physiology, 6th ed., Fox, SI; WC Brown, Fig.9.9
Somatic Motor
• Acetylcholine (ACh) acts on muscle
nicotinic ACh receptors
• Excitatory, causes muscle contraction
Somatic Motor Nervous System
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Cell bodies in CNS
Send single axons to skeletal muscles
Excitatory, causes muscle contraction
Acetylcholine (ACh) acts on
nicotinic ACh receptors
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.
Motor efferent pathways