Autonomic Nervous System Vocabulary Flashcards

These flashcards cover essential vocabulary and concepts relating to the Autonomic Nervous System, based on the lecture notes provided.

Autonomic Nervous System (ANS)

A system that regulates involuntary body functions such as heart rate and digestion.

Somatic Nervous System (SNS)

The part of the nervous system responsible for voluntary movements and reflexes.

Craniosacral Division

The anatomical origin of the parasympathetic division, encompassing brainstem and sacral spinal cord regions.

Thoracolumbar Division

The anatomical origin of the sympathetic division, located in the lateral horns of T1–L2.

Preganglionic Neuron

The first neuron in the autonomic motor pathway, extending from the CNS to an autonomic ganglion.

Postganglionic Neuron

The second neuron in the autonomic pathway, extending from the autonomic ganglion to the effector organ.

Neuronal Convergence

A phenomenon where multiple preganglionic neurons synapse on one ganglionic neuron.

Neuronal Divergence

A phenomenon where branches of one preganglionic neuron synapse with multiple ganglionic neurons.

Hypothalamus

A brain region essential for the regulation of the ANS, controlling emotional processes.

Parasympathetic Division

The part of the ANS associated with the 'rest-and-digest' response.

Sympathetic Division

The part of the ANS associated with the 'fight-or-flight' response.

Autonomic Ganglion

A cluster of neuronal cell bodies in the autonomic nervous system.

Acetylcholine (ACh)

A neurotransmitter released by many autonomic neurons, affecting both sympathetic and parasympathetic responses.

Norepinephrine (NE)

A neurotransmitter primarily associated with the sympathetic division of the ANS.

Cholinergic Neurons

Neurons that release acetylcholine as their neurotransmitter.

Adrenergic Neurons

Neurons that release norepinephrine as their neurotransmitter.

Nictonic Receptors

Receptors that respond to acetylcholine and are found on postganglionic neurons.

Muscarinic Receptors

Receptors found on target organs of the parasympathetic division.

Alpha Receptors

Adrenergic receptors typically activated by norepinephrine to cause stimulation.

Beta Receptors

Adrenergic receptors that can either stimulate or inhibit physiological responses depending on the subtype.

Autonomic Reflex

A visceral reflex involving receptors, sensory neurons, an integration center, motor neurons, and effectors.

Dual Innervation

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

Autonomic Plexuses

Networks of nerves that contain both sympathetic and parasympathetic fibers.

Celiac Ganglion

A prevertebral ganglion associated with the stomach and surrounding organs.

Adrenal Medulla

The inner part of the adrenal gland that releases hormones during the fight-or-flight response.

Enteric Nervous System

A division of the ANS that controls the gastrointestinal tract.

Visceral Sensory Neurons

Neurons that transmit sensory information from internal organs to the CNS.

Vagal Tone

The influence of the vagus nerve on heart rate by parasympathetic activity.

Vasomotor Tone

The continuous partial constriction of blood vessels due to sympathetic input.

Horner Syndrome

A condition caused by disruption of the sympathetic nerves in the neck, leading to ptosis and constricted pupils.

Raynaud Syndrome

A condition characterized by sudden constriction of small arteries, usually in response to stress or cold.

Gastrointestinal Reflex

An autonomic reflex involving the contraction of the rectum and relaxation of the anal sphincter.

Micturition Reflex

An autonomic reflex controlling the urination process.

Epinephrine

A hormone released by the adrenal medulla that enhances the ‘fight-or-flight’ response.

Ciliary Ganglion

A ganglion associated with the oculomotor nerve that controls pupil constriction.

Oculomotor Nerve (CN III)

A cranial nerve responsible for controlling eye movements and pupil constriction.

Facial Nerve (CN VII)

A cranial nerve that conveys parasympathetic signals to lacrimal and salivary glands.

Glossopharyngeal Nerve (CN IX)

A cranial nerve that controls parotid salivary gland secretion.

Vagus Nerve (CN X)

A cranial nerve that innervates many thoracic and abdominal organs.

Pelvic Splanchnic Nerves

Nerves that arise from the sacral region and innervate pelvic organs.

Adrenal Medulla Pathway

Pathway where preganglionic sympathetic axons stimulate the adrenal medulla cells.

Splanchnic Nerve Pathway

Pathway for effectors in abdominal viscera that do not synapse in the sympathetic trunk.

Intercostal Nerve

Nerves that provide sensory and motor innervation to the skin and muscles of the thorax.

Sympathetic Trunk Ganglia

Ganglia that run parallel to the vertebral column and are involved in the sympathetic response.

Preganglionic Axon

The axon of the first neuron in the autonomic pathway, which releases ACh.

Postganglionic Axon

The axon of the second neuron in the autonomic pathway, which releases either ACh or NE.

Sympathetic Trunk

A chain of ganglia located along the sides of the vertebral column involved in the sympathetic nervous system.

Vasoconstriction

The narrowing of blood vessels that increases blood pressure.