THE_AUTOMIC_NERVOUS-SYSTEM

Autonomic Nervous System (ANS)

Autonomic Nervous System (ANS)

The part of the nervous system responsible for controlling involuntary bodily functions, such as heart rate, digestion, and respiratory rate.

Somatic Nervous System (SNS)

The part of the nervous system responsible for voluntary control of body movements via skeletal muscles.

Sympathetic Division

The part of the autonomic nervous system that activates the body's fight or flight response, increasing alertness and metabolic rate.

Parasympathetic Division

The part of the autonomic nervous system that promotes rest and digest activities, reducing metabolic rate and conserving energy. Repose activities, stimulating visceral functions, conserving energy, and promoting relaxation.

Preganglionic Neurons

Neurons whose cell bodies are located in the CNS and extend their axons to synapse with postganglionic neurons in autonomic ganglia.

Ganglionic Neurons

Neurons located in autonomic ganglia that receive input from preganglionic neurons and extend their axons to innervate visceral effectors.

Autonomic Ganglia

Structures containing ganglionic neurons that innervate visceral effectors in the autonomic nervous system.

Collateral Ganglia

Ganglia located in the sympathetic pathways that innervate visceral organs in the abdominopelvic cavity.

Adrenal Medulla

The center of the adrenal gland considered a modified sympathetic ganglion, innervated by preganglionic fibers that secrete adrenaline and noradrenaline into the bloodstream.

White Rami

Myelinated preganglionic sympathetic axons that leave the spinal nerve and extend into a chain ganglion.

Gray Rami

Unmyelinated postganglionic sympathetic fibers that leave the chain ganglion and run back to join lumbar and sacral spinal nerves.

Sympathetic Pathways

Pathways of unmyelinated postganglionic fibers that control visceral effectors in different regions of the body.

Sympathetic Activation

Occurs during crisis and is controlled by sympathetic centers in the hypothalamus, leading to various physiological responses.

Sympathetic Effects

Stimulation of sympathetic preganglionic neurons releases acetylcholine, leading to excitatory effects on target organs.

Sympathetic Receptors

Respond primarily to norepinephrine and epinephrine, including alpha and beta receptors that trigger metabolic changes in target cells.

Sympathetic Neurotransmitters

Include acetylcholine, norepinephrine, and nitric oxide, which play roles in innervating different tissues and organs in the body.

Acetylcholine

The neurotransmitter released by both preganglionic and postganglionic fibers in the parasympathetic nervous system.

Ganglia

Clusters of nerve cell bodies located outside the central nervous system, where synapses occur between neurons.

Terminal Ganglion

A type of peripheral ganglion located near the target organ and usually unpaired.

Intramural Ganglion

A type of peripheral ganglion embedded in the tissues of the target organ, forming interconnected masses by clusters of ganglion cells.

Nicotinic Receptors

Receptors found in the somatic motor system and on ganglion cells in both the sympathetic and parasympathetic divisions, causing excitation when activated.

Muscarinic Receptors

Receptors found at neuromuscular and neuroglandular junctions in the parasympathetic nervous system, leading to either excitatory or inhibitory responses depending on enzyme activation.

Parasympathetic Effects

Responses to parasympathetic activity including constriction of respiratory passageways, decrease in heart rate, increased secretion by glands, and more.

Adrenergic Receptors

Receptors found in the autonomic nervous system that respond to adrenaline or noradrenaline, leading to various physiological responses.

Cholinergic Receptors

Receptors found in the autonomic nervous system that respond to acetylcholine, leading to various physiological responses.

Dual Innervation

The concept where most internal organs receive signals from both the sympathetic and parasympathetic nervous systems, leading to opposing effects.

Aortic arch

The curved portion of the aorta between the ascending and descending parts.

Autonomic Plexuses and Ganglia

Networks of nerves that control involuntary bodily functions.

Esophagus

The muscular tube connecting the throat (pharynx) with the stomach.

Celiac plexus and ganglion

A network of nerves located in the abdomen that controls the digestive system.

Enteric Nervous System (ENS)

Nervous system within the walls of the digestive system that can function independently of the central nervous system.

Sympathomimetic drugs

Drugs that mimic the effects of epinephrine or norepinephrine.