The Autonomic Nervous System and Visceral Reflexes

These flashcards cover key vocabulary terms related to the Autonomic Nervous System (ANS), its divisions, functions, and associated reflexes as discussed in the lecture.

Autonomic Nervous System (ANS)

A motor nervous system that controls glands, cardiac muscle, and smooth muscle.

Visceral Motor Division

Another name for the Autonomic Nervous System; regulates primitive body functions.

Sympathetic Division

Part of the ANS responsible for the 'fight or flight' response, preparing the body for physical activity.

Parasympathetic Division

Part of the ANS responsible for 'rest and digest' functions, promoting calm and body maintenance.

Efferent Pathways

The pathways that carry signals away from the central nervous system to the target organs.

Preganglionic Fibers

Nerve fibers that extend from the CNS to synapse with postganglionic neurons in the ANS.

Postganglionic Fibers

Nerve fibers that extend from ganglia to the target organ in the ANS.

Baroreflex

A visceral reflex used to control blood pressure through a negative feedback loop.

Cholinergic Fibers

Nerve fibers that secrete acetylcholine (ACh).

Adrenergic Fibers

Nerve fibers that secrete norepinephrine (NE).

Dual Innervation

When an organ receives input from both the sympathetic and parasympathetic divisions of the ANS.

Neural Divergence

The branching of a single preganglionic fiber to multiple postganglionic fibers in the sympathetic division.

Vagus Nerve

The cranial nerve that plays a crucial role in parasympathetic control of the heart and digestive tract.

ACh

Acetylcholine, a neurotransmitter released by cholinergic fibers.

NE

Norepinephrine, a neurotransmitter released by adrenergic fibers.

Sympathomimetics

Drugs that enhance sympathetic responses.

Parasympatholytics

Drugs that inhibit acetylcholine release or block its receptors.

Epinephrine

A hormone that is more active on Beta receptors, influencing heart and lung functions.

Norepinephrine

A hormone that is more active on alpha receptors, influencing blood pressure.

Megacolon

A condition caused by a failure of neural crest cells to migrate, leading to a lack of motility in the colon.