Autonomic Nervous System Overview

Flashcards covering key concepts related to the Autonomic Nervous System, its structure, function, and effects.

Autonomic Nervous System (ANS)

A division of the nervous system that supplies smooth muscle, cardiac muscle, and glands.

Dual Innervation

Most organs/glands are supplied by two divisions of the ANS that have opposite effects; one is excitatory (Sympathetic) and one is inhibitory (Parasympathetic).

Sympathetic Division

Controlling 'Fight or Flight' responses, it originated from the thoracolumbar division and involves short preganglionic fibers and long postganglionic fibers.

Parasympathetic Division

Controlling 'Rest and Digest' functions, it is craniosacral outflow involving long preganglionic fibers and short postganglionic fibers.

Cholinergic Receptors

Receptors that bind acetylcholine; includes nicotinic and muscarinic receptors.

Adrenergic Receptors

Receptors that respond to epinephrine and norepinephrine; subdivided into alpha and beta receptors.

Sympathetic vs. Parasympathetic Effects

Sympathetic effects generally increase heart rate and blood pressure (e.g., dilate bronchioles), while parasympathetic effects decrease heart rate and increase digestive activity.

Preganglionic Neurons

Neurons that extend from the CNS to ganglia and release acetylcholine in both ANS divisions.

Postganglionic Neurons

Neurons that extend from ganglia to effector organs; sympathetic neurons may release norepinephrine while parasympathetic neurons release acetylcholine.

Hypothalamus

The part of the brain that controls the autonomic nervous system, hunger, thirst, thermoregulation, emotions, and sexuality.