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Peripheral Nervous System
A&P
Peripheral Nervous System
Consists of the nervous tissue that lies outside the central nervous system
Interacts through the 12 cranial nerves and 31 spinal nerves
Nerve: enclosed, cable-like bundle of axons
Parts of the PNS
Roots of the Spinal Nerves:
dorsal root: “nerve highway” that carries sensory information from sensory receptors in the body to the CNS
ventral root: contains axons of motor neurons that carry information away from the CNS to the muscles and glands of the body.
Parts of PNS
The sensory division, also known as the afferent division, carries sensory information from sensory receptors in the body to the CNS.
The motor division, or efferent division, carries nerve impulses from the CNS to the muscles, glands, and organs of the body.
Parts of PNS
Motor Divisions of the PNS
Two parts:
1. Autonomic
2. Somatic
Motor Divisions of the PNS
Somatic Nervous System
Somatic Nervous System
associated with the conscious (voluntary) control of the body through the movement of skeletal muscles and the perception of external stimuli through senses such as touch, hearing, and sight
includes all the neurons that are connected with muscles, skin, and sensory organs
made up of sensory nerves and motor nerves
Autonomic Nervous System
Autonomic Nervous System
A reflex is an automatic (involuntary) action that is caused by a defined stimulus and is carried out through a reflex arc.
maintains homeostasis in the body
AKA involuntary nervous system
Divisions of the ANS
2 divisions:
-sympathetic: generally stimulates body systems during emergency situations
aka fight or flight
-parasympathetic: controls non-emergency functions such as digestion