Peripheral Nervous System (PNS) Lecture Notes

These flashcards cover key concepts related to the Peripheral Nervous System (PNS) from the lecture, encompassing its structure, function, and components.

Peripheral Nervous System (PNS)

The part of the nervous system outside the central nervous system (CNS) that carries information to and from the body.

Sensory Division

Carries information towards the central nervous system (CNS) and is responsible for sensory input.

Motor Division

Carries information away from the central nervous system (CNS) and is responsible for motor output.

Somatic Division

Part of the motor division that controls skeletal muscle and allows voluntary control of movement.

Autonomic Division

Part of the motor division that controls cardiac and smooth muscle, allowing involuntary control.

Sympathetic Division

Part of the autonomic nervous system that controls 'fight or flight' responses.

Parasympathetic Division

Part of the autonomic nervous system that controls 'rest and digest' responses.

Cranial Nerves

Twelve pairs of nerves that originate from the brain and supply muscles and sensations to the head and neck.

Referred Pain

Pain perceived in a different area of the body that arises from an organ due to similar neural pathways.

Axon Regeneration

The process by which damaged axons in the peripheral nervous system can regrow when the cell body remains intact.

Spinal Nerves

31 pairs of nerves that exit the spinal cord; these carry both sensory and motor information.

Dermatome

An area of skin that is mainly supplied by a single spinal nerve root.

Somatic Reflexes

Involuntary movements in response to stimuli, designed to protect the body from injury.

Mixed Nerves

Nerves that contain both sensory (afferent) and motor (efferent) neurons.

Phasic Receptors

Sensory receptors that adapt quickly and stop responding to constant stimuli.

Tonic Receptors

Sensory receptors that continue to respond as long as a stimulus is present.

Schwann Cells

Cells that form myelin sheaths around axons in the peripheral nervous system, aiding in axon regeneration.

Wallerian Degeneration

The process that occurs when an axon is cut, involving breakdown of the axon distal to the injury.

Striking the Patellar Tendon

A reflex action that activates the quadriceps muscle through muscle spindle receptors.

Cervical Plexus

A network of nerves formed from the ventral rami of cervical spinal nerves that supply the head and neck.

Brachial Plexus

A network of nerves formed from the ventral rami of spinal nerves that supplies the shoulder and arm.

Lumbar Plexus

A network of nerves that supplies the anterior and medial aspects of the leg.

Sacral Plexus

A network of nerves formed from the ventral rami of spinal nerves that supplies the posterior leg.