James Madison University BIO 270: Chapter 7-The peripheral nervous system; efferent division- Lecture notes

Chapter 7
The peripheral nervous system:
efferent division

, PNS: the efferent division
• Provides the link between the
CNS and the muscles & glands
– Much efferent output is
directed at maintaining
homeostasis
• Two divisions:
– Autonomic nervous system Afferent
(ANS)
• Involuntary branch of PNS
• Innervates cardiac muscle,
smooth muscle, most exocrine
(sweat) glands, some endocrine Efferent

glands and adipose tissue
– Somatic nervous system
• Voluntary control
• Innervates skeletal muscle

, Autonomic nervous system
• Autonomic nerve pathway
– Extends from CNS to effector organ
– Only two neurotransmitters control effector organ responses:
acetylcholine (ACh) and epinephrine/norepinephrine (Epi, NE)
– Two neuron chain:
• Preganglionic neuron/fiber – from CNS to cell body of second
(postganglionic) neuron
• Postganglionic neuron/fiber – from preganglionic terminal to effector organ