The Peripheral Nervous System

what does the PNS do?

plays a role in regulating movement and the internal environment

what is the PNS composed of?

afferent and efferent systems

afferent system?

receives info from receptors and transmits it to the CNS

efferent system?

carries signals away from the CNS to muscle or glands

efferent system divided into:

1. somatic system

2. automatic system

somatic system controls?

controls body movements using 31 pairs of spinal nerves which serve different body parts

somatic system is c and v?

conscious and voluntary

what does the somatic system serve?

some unconscious movements including reflexes, shivering, body posture and balance

automatic system works w who?

works w the endocrine system to regulate and respond to changes in the environment

what does the automatic system control?

involuntary processes (digestion, sweating, breathing, circulation, reproductive, and excretory functions) by contracting smooth muscles

what is the automatic system divided into?

1. sympathetic division

2. parasympathetic division

theyre always active and oppose one another

what does the sympathetic division do?

prepares the body for fight or flight response by increasing heart rate and blood pressure, dilating the bronchi and pupils and by suppressing digestion

what does the parasympathetic division do?

reduces the affects of the sympathetic division and allows maintenance activities to occur (digestion and urination)