Autonomic Nervous System Overview

These flashcards cover key concepts related to the autonomic nervous system, including its structure, functions and differentiations between sympathetic and parasympathetic divisions.

Autonomic Nervous System (ANS)

The functional division of the nervous system providing involuntary stimulation of effectors such as cardiac muscle, smooth muscle, and glands.

Sympathetic ANS

One of the subdivisions of the ANS, typically associated with 'fight or flight' responses, increasing heart rate and respiration.

Parasympathetic ANS

One of the subdivisions of the ANS, commonly associated with 'rest and digest' activities, decreasing heart rate and increasing digestive activities.

Preganglionic neuron

The first neuron in an autonomic motor pathway that carries impulses to a ganglion.

Postganglionic neuron

The second neuron in an autonomic motor pathway that carries impulses to target effectors.

Autonomic tone

The constant level of signal from both sympathetic and parasympathetic divisions to the organs.

Acetylcholine (Ach)

A neurotransmitter released by the first neuron in all motor pathways, both somatic and autonomic.

Norepinephrine

A neurotransmitter typically released by the second neuron in sympathetic autonomic pathways.

Cardiac muscle

A type of muscle that the autonomic nervous system stimulates involuntarily.

Glandular secretion

The release of substances from glands that can be stimulated by the autonomic nervous system.

Cranial nerves

Nerves that carry parasympathetic fibers; includes Oculomotor, Facial, Glossopharyngeal, and Vagus nerves.

Thoracic and abdominal innervation

The area innervated by the vagus nerve, conducting approximately 80% of all parasympathetic fibers.

Sympathetic trunk

A series of ganglia located close to the spinal cord through which sympathetic pathways travel.

Adrenal medulla pathway

A unique sympathetic pathway where the preganglionic axon continues to the adrenal medulla without synapsing with a postganglionic neuron.

Vasoconstriction

The process in which blood vessels constrict, typically stimulated by the sympathetic ANS.

Vasodilation

The process in which blood vessels dilate, typically stimulated by the parasympathetic ANS.