Chapter 15 The autonomic nervous system

Define the autonomic nervous system (ANS).

A nervous system that controls cardiac muscles, smooth muscles, and glands

Summarize functions of the ANS, including the influence of the general visceral senses.

Carries out actions involuntarily. Regulates heart rate, digestion, and pupil contraction. -Visceral reflexes (senses): unconscious, automatic, stereotyped responses to stimulation involving visceral receptors and effectors.

Name the cranial nerves that support parasympathetic fibers

Cranial nerves that support the parasympathetic division. CN III Olfactory CNVII Facial CN IX Glossopharyngeal CN X Vagus

Give examples of "fight or flight" responses experienced by your body.

Getting scared, pupils dilate, heart rate increases and breathing increases.

Name examples of "resting and digesting" responses experienced by your body.

Heart rate slows down, blood pressure lowered, and digestion occurs.

Distinguish preganglionic from postganglionic neurons

Preganglionic neurons are attached to the CNS, and Postganglionic neurons are attached to the targeted muscle (outside of the CNS)

Outline the basic functional differences between the sympathetic and parasympathetic divisions of the ANS.

Sympathetic (Fight or Flight): Works during extreme situations. (exercise, excitement, emergencies). Helps respond to dangerous situations (increase heart rate and breathing rate. Increases blood and oxygen to skeletal muscles, Inhibits mobility to the digestive and urinary tracts.) Parasympathetic (Rest and Digest): Active when body is at rest. Digestion, elimination of feces and urine. Heart rate and respiration at low-normal levels.

Name the two divisions of the ANS

Sympathetic and Parasympathetic

Describe three major anatomical differences between the sympathetic and parasympathetic divisions.

Sympathetic: 1. Called the thoracolumbar division- originates from spinal segments T1-L2 2. Lon postganglionic fibers 3. Highly branched; influence many organs at once. Parasympathetic: 1. Called the craniosacral division 2. Short postganlionic fibers 3. Few branches; only localized effect.

Describe major biochemical differences between the sympathetic and parasympathetic neurotransmitters

Sympathetic: releases norepinephrine (adrenergic) Parasympathetic: release acetylcholine (cholinergic)

Explain how the parasympathetic division relates to the sacral spinal cord, and describe sacral outflow.

The Parasympathetic division innervates the sacral area through the lower end of the spinal cord.

Distinguish effectors of the ANS from the effectors of the rest of the motor (efferent) division.

effectors of the ANS stimulate the glands, cardiac muscle, and smooth muscles whereas the motor efferent division stimulates skeletal muscle for movement. ANS also regulates heart rate, respiration, digestion, and pupil contraction.