Overview of the Peripheral Nervous System

These flashcards cover key terms and concepts related to the Peripheral Nervous System and its subdivisions, aiding in exam preparation.

Peripheral Nervous System (PNS)

Made up of nerves that attach to the Central Nervous System (CNS), including spinal and cranial nerves.

Central Nervous System (CNS)

Composed of the brain and spinal cord.

Autonomic Nervous System (ANS)

Controls involuntary functions in smooth and cardiac muscles through two neuronal pathways.

Sympathetic Division

A subdivision of the ANS responsible for the 'fight or flight' response.

Parasympathetic Division

A subdivision of the ANS that regulates resting functions; known as 'rest and digest'.

Preganglionic Neuron

Neurons that originate in the CNS and synapse with ganglionic neurons.

Postganglionic Neuron

Neurons that receive signals from preganglionic neurons and innervate effectors.

Dual Innervation

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

Acetylcholine (ACh)

A neurotransmitter released by all preganglionic neurons in the ANS.

Adrenergic Receptors

Receptors that bind norepinephrine and epinephrine, primarily involved in the sympathetic response.

Nicotinic Receptor

A type of acetylcholine receptor located on all ganglion cells of the ANS.

Muscarinic Receptor

A type of acetylcholine receptor primarily found in the parasympathetic system.

Vagus Nerve (CN X)

A key nerve of the parasympathetic nervous system that regulates many autonomic functions.

Ganglion

A collection of neuron cell bodies in the PNS.

Autonomic Tone

The balance of sympathetic and parasympathetic activity, maintaining homeostasis in organs.

Epinephrine

A hormone released by the adrenal glands involved in the fight-or-flight response.

Norepinephrine

A neurotransmitter used by sympathetic postganglionic fibers, affecting various target organs.

Neurogenic Shock

A condition resulting from severe loss of sympathetic stimulation, leading to blood vessel dilation.

Sympathetic Chain Ganglia

A series of ganglia in the sympathetic nervous system located close to the spinal cord.

Collateral Ganglia

Ganglia that are further from the spinal cord, innervating organs in the abdominal cavity.

Splanchnic Nerves

Nerves that carry fibers from the sympathetic nervous system to the abdominal organs.

Visceral Effectors

Organs such as smooth muscles, cardiac muscles, and glands innervated by the ANS.

Cauda Equina

A bundle of spinal nerves and spinal nerve rootlets located in the vertebral canal.