Autonomic Nervous System Review

Vocabulary flashcards covering the divisions, structures, chemical signaling, central control, and pharmacology of the Autonomic Nervous System based on Chapter 15.

Autonomic Nervous System (ANS)

Derived from "Auto" (self) and "nomous" (control), this system controls most visceral functions of the body and is designed to maintain homeostasis.

Sympathetic Division

The division associated with the "fight-or-flight" response and thoracolumbar outflow from the spinal cord.

Parasympathetic Division

The division associated with the "rest and digest" response and craniosacral outflow from the brain stem and sacral spinal cord.

Sympathetic Chain Ganglia

A series of 23 ganglia that runs alongside the vertebral column where nerves travel from the spinal cord to target effectors.

Preganglionic Fiber (Sympathetic)

A short, myelinated fiber that travels from the spinal cord to the sympathetic ganglion.

Postganglionic Fiber (Sympathetic)

A long, unmyelinated fiber that travels from the ganglion to the target effector.

Adrenal Medulla

A structure that receives direct connection from preganglionic fibers to release molecules directly into the system.

Terminal Ganglia

Parasympathetic ganglia located right next to the target organ.

Intramural Ganglia

Parasympathetic ganglia located within the wall of the target organ.

Cholinergic Synapse

A synapse where Acetylcholine ($ACh$) is released to either nicotinic (ligand-gated channel) or muscarinic (G-protein receptor) receptors.

Adrenergic Synapse

A synapse where norepinephrine or epinephrine (adrenaline) is released to either alpha or beta receptors.

Norepinephrine

A molecule that functions as both a neurotransmitter and a hormone within the adrenergic signaling system.

Autonomic Varicosities

Chains of swellings on postganglionic axons that release neurotransmitters such as Acetylcholine ($ACh$) and Norepinephrine.

Baroreceptors

Specialized receptors in the aorta and carotid arteries that react to stretch stimuli to help maintain homeostasis.

Referred Pain

The conscious perception of autonomic sensation, where visceral sense is strong enough to be felt in unexpected places.

Long Reflex

An autonomic reflex involving afferent branches that enter the spinal cord or brain and involve efferent branches.

Short Reflex

A completely peripheral reflex involving local integration of sensory input and motor output, such as the Enteric Nervous system.

Autonomic Tone

The balance resulting from the competing signals of the sympathetic and parasympathetic divisions working to maintain homeostasis.

Hypothalamus

The forebrain structure responsible for autonomic and endocrine function, which sends output through the dorsal longitudinal fasciculus and the medial forebrain bundle.

Amygdala

A structure in the limbic lobe involved in emotional response and memory that can stimulate the fight-or-flight response via the hypothalamus.

Medulla

The cardiovascular center that controls smooth and cardiac muscle and receives sensory information about blood pressure and cardiac function.

Sympathomimetic Drugs

Drugs, such as phenylephrine, cocaine, or caffeine, that bind to adrenergic receptors or increase norepinephrine release to mimic sympathetic action.

Sympatholytic Drugs

Drugs, such as beta blockers (e.g., propanolol or metoprolol), that act as antagonists to adrenergic receptors by blocking the binding of NE or epinephrine.

Parasympathomimetic Drugs

Muscarinic agonists, such as pilocarpine, that enhance cholinergic effects and can be used for eye disorders to constrict pupils.

Anticholinergic Drugs

Muscarinic antagonists, such as atropine or scopolamine, that inhibit cholinergic effects and can lead to pupil dilation.