Chapter 16: The Nervous System - Autonomic Nervous System

A collection of vocabulary flashcards covering key terms and concepts from Chapter 16 on the Autonomic Nervous System.

Autonomic Nervous System (ANS)

A part of the nervous system that controls involuntary bodily functions, such as the activity of glands, cardiac muscle, and smooth muscle.

Visceral Motor System

A component of the ANS responsible for involuntary control of effectors like glands and smooth muscle.

Visceral Reflexes

Unconscious, automatic responses of visceral effectors to stimuli.

Sympathetic Division

The part of the ANS that triggers the 'fight-or-flight' response, increasing heart rate and blood flow to muscles.

Parasympathetic Division

The part of the ANS involved in 'rest and digest' activities, decreasing heart rate and stimulating digestion.

Autonomic Tone

The balance between the activity of sympathetic and parasympathetic nervous systems.

Preganglionic Fiber

The fiber in the ANS that runs from the CNS to a ganglion.

Postganglionic Fiber

The fiber in the ANS that extends from the ganglion to the target organ.

Somatic Nervous System

Part of the nervous system controlling voluntary movements of skeletal muscles.

Effectors

Muscle or gland tissues that respond to signals from the nervous system.

Efferent Pathways

Nerve pathways that carry signals away from the CNS to effectors.

Thoracolumbar Division

Another name for the sympathetic division, due to the origin of its preganglionic neurons in the thoracic and lumbar regions.

Craniosacral Division

Another name for the parasympathetic division, as it arises from the brain and sacral region of the spinal cord.

Sympathetic Chain Ganglia

A series of interconnected ganglia located adjacent to the spinal column.

Terminal Ganglia

Ganglia located in or near the target organ for the parasympathetic division.

Enteric Nervous System

The nervous system of the digestive tract, regulating functions like motility and secretion.

Raynaud Disease

A condition characterized by paleness and pain in digits due to excessive vasoconstriction.

Horner Syndrome

A condition that involves unilateral pupillary constriction and eyelid sagging due to sympathetic division lesions.

Effect on Target Cells

In the ANS, effects can be excitatory or inhibitory, while in the somatic system, effects are always excitatory.

Short Preganglionic Fibers

Fibers in the sympathetic division that are relatively short compared to the postganglionic fibers.

Long Preganglionic Fibers

Fibers in the parasympathetic division that are relatively long compared to the postganglionic fibers.

Smooth Muscle

Involuntary muscle found in the walls of organs and vessels, controlled by the ANS.

Cardiac Muscle

Muscle tissue of the heart, controlled by the autonomic nervous system.

Involuntary Control

Regulation of body functions without conscious thought, primarily managed by the ANS.

Skeletal Muscle

Voluntary muscle that is controlled by the somatic nervous system.

Ganglia

Clusters of nerve cell bodies in the ANS where preganglionic and postganglionic fibers synapse.

Efferent Pathways of ANS

Consists of two nerve fibers from the CNS to the effector, requiring a synapse at a ganglion.