Autonomic Nervous System

A collection of flashcards covering key terms and concepts related to the autonomic nervous system.

Autonomic Nervous System

System responsible for involuntary bodily functions such as heart rate, digestion, and respiratory rate.

Sympathetic Nervous System

Part of the autonomic nervous system that initiates the 'fight or flight' response.

Parasympathetic Nervous System

Part of the autonomic nervous system that promotes the 'rest and digest' response.

Preganglionic Fibers

Nerve fibers that extend from the central nervous system to the ganglia in the autonomic nervous system.

Postganglionic Fibers

Nerve fibers that extend from the autonomic ganglia to the target effector organs.

Acetylcholine (ACh)

Neurotransmitter released by preganglionic fibers in both sympathetic and parasympathetic divisions.

Norepinephrine (NE)

Neurotransmitter predominantly released by postganglionic sympathetic fibers.

Alpha-1 Receptors

Adrenergic receptors that mediate vasoconstriction and smooth muscle contraction.

Beta-1 Receptors

Adrenergic receptors that increase heart rate and contractility.

Beta-2 Receptors

Adrenergic receptors that promote smooth muscle relaxation in the respiratory tract.

Muscarinic Receptors

Cholinergic receptors in the parasympathetic nervous system that respond to acetylcholine.

Homeostasis

The body's ability to maintain a stable internal environment despite changes in external conditions.

Visceral Reflexes

Reflexes that involve autonomic pathways and effectors like smooth muscle and glands.

Baroreceptor Reflex

A reflex that helps regulate blood pressure via autonomic feedback mechanisms.

Mydriasis

Dilation of the pupil, typically due to sympathetic stimulation.

Miosis

Contraction of the pupil, typically due to parasympathetic stimulation.

Ciliary Muscle

Muscle in the eye that adjusts the lens for focus; controlled by the autonomic nervous system.

Splanchnic Nerve

Nerve involved in innervating abdominal and pelvic organs.

Vagal Tone

The level of activity of the vagus nerve, which is high during relaxation and digestion.

Physiological Response

The body's physical reaction to stimuli such as stress or food intake.

Dendrite

Branching extensions of a neuron that receive signals from other neurons.

Ganglion

A cluster of neuron cell bodies in the peripheral nervous system.

Efferent Nerves

Nerves that carry signals away from the central nervous system to effectors.

Afferent Nerves

Nerves that carry sensory signals to the central nervous system.

Cranial Nerves

Nerves emerging directly from the brain, including those involved in the parasympathetic system.

Sacral Nerves

Nerves from the lower part of the spinal cord that contribute to the parasympathetic system.

Visceral Afferent

Nervous signals that convey information from internal organs to the central nervous system.