Autonomic Nervous System Flashcards

Flashcards reviewing the key concepts of the autonomic nervous system.

Somatic Nervous System

Controls voluntary movements; targets skeletal muscles.

Autonomic Nervous System

Controls involuntary responses; targets smooth muscle, cardiac muscle, and glands.

Somatic Lower Motor Neuron

Consists of a single motor neuron that extends from the spinal cord to skeletal muscle.

Autonomic Lower Motor Neuron

Involves two neurons: preganglionic and postganglionic. Preganglionic neurons synapse in an autonomic ganglion.

Somatic Neurotransmitter

Releases acetylcholine (ACh).

Autonomic Neurotransmitter

Preganglionic neurons release ACh; postganglionic neurons release ACh or norepinephrine (NE).

Somatic Lower Motor Neuron Axons

Myelinated.

Autonomic Lower Motor Neuron Axons

Preganglionic axons are myelinated; postganglionic axons are unmyelinated.

Hypothalamus

The primary integration and command center for autonomic functions.

Sympathetic Nervous System Origin

Originates from the thoracic and lumbar regions of the spinal cord (T1-L2).

Parasympathetic Nervous System Origin

Originates from the brainstem (CN III, VII, IX, X) and sacral region of the spinal cord (S2-S4).

Sympathetic Nervous System Function

Prepares the body for 'fight or flight' responses; increases heart rate, dilates pupils, etc.

Parasympathetic Nervous System Function

Promotes 'rest and digest' functions; slows heart rate, constricts pupils, stimulates digestion, etc.

Sympathetic Nervous System Effect on Pupils

Pupil dilation.

Parasympathetic Nervous System Effect on Pupils

Pupil constriction.

Sympathetic Nervous System Effect on Heart Rate

Increased heart rate and force of contraction.

Parasympathetic Nervous System Effect on Heart Rate

Decreased heart rate.

Sympathetic Nervous System Effect on Airways

Airway dilation.

Parasympathetic Nervous System Effect on Airways

Airway constriction.

Sympathetic Nervous System Effect on Digestion

Decreased digestive activity.

Parasympathetic Nervous System Effect on Digestion

Increased digestive activity.

Sympathetic Nervous System Effect on Reproduction

Stimulates ejaculation in males and vaginal contractions in females.

Parasympathetic Nervous System Effect on Reproduction

Stimulates erection in males and clitoral engorgement in females.

Types of Cholinergic Receptors

Muscarinic and Nicotinic

Types of Adrenergic Receptors

Alpha and Beta