ANS

Peripheral Nervous System (PNS)

Part of the nervous system outside the brain and spinal cord, including sensory and motor divisions.

Motor (efferent) division

The part of the PNS that sends commands from the CNS to effectors (muscles/glands).

Effectors

Muscles or glands that respond to nervous system commands.

Somatic Motor Division

Controls voluntary movements and targets skeletal muscles.

Visceral Motor Division

Another name for the autonomic nervous system, controlling involuntary actions in smooth muscle, cardiac muscle, and glands.

Autonomic Nervous System (ANS)

The part of the nervous system controlling involuntary actions like heart rate and digestion.

Sympathetic Division

The division of the ANS responsible for 'fight-or-flight' responses.

Parasympathetic Division

The division of the ANS responsible for 'rest-and-digest' responses.

Dual innervation

When an organ receives input from both sympathetic and parasympathetic divisions, often with opposite effects.

Acetylcholine (ACh)

A neurotransmitter used in both the somatic and autonomic nervous systems.

Norepinephrine (NE) and Epinephrine (Epi)

Neurotransmitters primarily used by the sympathetic division to stimulate target tissues.

Sympathetic chain

A network of interconnected sympathetic ganglia near the spinal cord.

Adrenal cortex

The outer layer of the adrenal gland that releases hormones like cortisol.

Adrenal medulla

The inner part of the adrenal gland that secretes epinephrine and norepinephrine.

Adrenergic receptor

A receptor that binds norepinephrine or epinephrine, mediating sympathetic effects.

Cholinergic receptor

A receptor that binds acetylcholine, mediating parasympathetic effects.

Muscarinic receptor

A type of cholinergic receptor found on target tissues in the parasympathetic division.

Nicotinic receptor

A type of cholinergic receptor found in autonomic ganglia and the somatic nervous system.

Vasomotor tone

The constant, low-level stimulation of blood vessels by the sympathetic division to maintain blood pressure.

Sympathomimetic drugs

Drugs that mimic the effects of the sympathetic division.

Parasympathomimetic drugs

Drugs that mimic the effects of the parasympathetic division.