Ch. 15 Autonomic Nervous System

Autonomic Nervous System

Primarily controls cardiac muscle, smooth muscle, and glands.

Rest and Digest

Functions of the parasympathetic division.

Sympathetic Division Origin

Originates from the thoracic and lumbar regions of the spinal cord.

Adrenal Medulla

A special case in the sympathetic division where preganglionic fibers directly synapse onto the target.

Sympathetic Chain Ganglia Function

Allow for widespread sympathetic responses by connecting to multiple spinal levels.

Chain Connection

Describes a preganglionic fiber that synapses at a different level than its origin.

Cranial Component of Parasympathetic Nervous System

Includes cranial nerves CN III, VII, IX, and X.

Vagus Nerve (CN X)

The major parasympathetic nerve responsible for innervating thoracic and abdominal organs.

Glossopharyngeal Nerve (CN IX)

Controls the parotid gland.

Oculomotor Nerve (CN III) Function

Responsible for pupil constriction.

Preganglionic Autonomic Neurons Neurotransmitter

All release acetylcholine.

Postganglionic Sympathetic Neurons Neurotransmitter

Primarily release norepinephrine.

Receptors Activated by Acetylcholine

Nicotinic receptors on postganglionic neurons.

Unique Sympathetic Fibers

Innervate sweat glands by releasing acetylcholine onto muscarinic receptors.

Autonomic Reflex Description

Includes an additional synapse at an autonomic ganglion.

Heart at Rest Influence

Primarily under the influence of parasympathetic tone.

Short Reflex

Type of autonomic reflex that bypasses the central nervous system and is entirely processed in peripheral ganglia.

Primary Integrative Center for Autonomic Control

Hypothalamus.

Drug Enhancing Sympathetic Function

Sympathomimetic.

Beta-blockers

An example of sympatholytic drugs.