Chapter 15 - Autonomic Nervous System Study Guide

These flashcards cover key vocabulary and concepts related to the Autonomic Nervous System (ANS), including its functions, structures, and related pharmacological interventions.

Autonomic Nervous System (ANS)

Also known as the Visceral Motor System, it controls the automatic, involuntary actions of internal organs.

Homeostasis

The regulation of unconscious processes that maintain stable internal conditions in the body, including blood pressure and body temperature.

Biofeedback

Processes that allow for limited conscious control of the ANS.

Visceral Reflexes

Unconscious, automatic responses triggered by the stimulation of glands, cardiac, or smooth muscle.

Efferent Neurons

Neurons that carry motor signals from the central nervous system to effectors.

Sympathetic Division

Part of the ANS associated with the 'fight or flight' response, increasing heart rate and blood pressure.

Parasympathetic Division

Part of the ANS associated with 'rest and digest' functions, calming the body and assisting with maintenance.

Autonomic Tone

The normal rate of activity indicating the balance between sympathetic and parasympathetic systems.

Splanchnic Nerves

Nerves that provide signals to and from visceral organs and blood vessels.

Preganglionic Neurons

Neurons that originate from the CNS and synapse in ganglia before connecting to postganglionic fibers.

Neuronal Convergence

When each postganglionic neuron receives signals from multiple preganglionic neurons.

Neuronal Divergence

When each preganglionic neuron branches and synapses on multiple postganglionic neurons, leading to widespread effects.

Catecholamines

Hormones such as epinephrine and norepinephrine, involved in the body's stress response.

Adrenergic Fibers

Fibers that secrete norepinephrine, typically found in postganglionic sympathetic fibers.

Cholinergic Fibers

Fibers that secrete acetylcholine.

Nicotinic Receptors

Receptors located on all ANS postganglionic neurons and adrenal medulla; ACh binding is generally excitatory.

Muscarinic Receptors

Receptors located on smooth and cardiac muscle as well as glands; ACh binding can be either excitatory or inhibitory.

Antagonistic Effects

Opposing effects of the sympathetic and parasympathetic systems on the same organ, such as heart rate regulation.

Cooperative Effects

When both divisions act on different effectors to produce a unified response, such as salivation.

Sympathomimetics

Agents that enhance sympathetic activity, such as ephedrine.

Sympatholytics

Agents that suppress sympathetic activity, like beta-blockers.

Parasympathomimetics

Agents that enhance parasympathetic activity, such as pilocarpine.

Parasympatholytics

Agents that inhibit ACh release or block receptors, like atropine.