CH7 The peripheral nervous system

the peripheral nervous system (PNS)

contains all the parts of the nervous system other than the brain and spinal cord

somatic PNS, visceral PNS

the two parts of the peripheral nervous system

somatic PNS

all the spinal nerves that innervate the skin, the joints, and the muscles that are under voluntary control

somatic motor axons

commands muscle contraction and are derived from motor neurons in the ventral spinal cord. mostly lie within the CNS but their axons are mostly in the PNS.

dorsal root ganglia

The cell bodies of the somatic sensory neurons lie outside the spinal cord in clusters called dorsal root ganglia.

visceral PNS / autonomic nervous system (ANS)

consists of the neurons that innervate the internal organs, blood vessels, and glands. mediates emotional, involuntary reactions

visceral sensory axons..

bring information about visceral function to the CNS

visceral motor fibres…

command the contraction and relaxation of smooth muscles, the rate of cardiac muscle contraction, and the secretory function of various glands.

afferent, efferent

terms used to indicate whether axons are transporting information toward or away from a point.

afferent

“carry to”

efferent

“carry from”