Peripheral Nervous System Overview

These flashcards cover key vocabulary and concepts related to the Peripheral Nervous System, its structure, functions, and classifications.

Peripheral Nervous System (PNS)

Consists of all neural structures outside the brain and spinal cord; provides links between the body and the external environment.

Sensory Receptors

Specialized structures responding to environmental changes, activating graded potentials that trigger nerve impulses.

Afferent Division

The sensory division of the PNS that transmits impulses to the CNS.

Efferent Division

The motor division of the PNS that transmits impulses away from the CNS to effectors.

Mechanoreceptors

Receptors that respond to touch, pressure, vibration, and stretch.

Thermoreceptors

Receptors that are sensitive to changes in temperature.

Photoreceptors

Receptors that respond to light energy, such as those in the retina.

Nociceptors

Receptors that are sensitive to pain-causing stimuli, such as extreme temperatures or pressure.

Externoceptors

Receptors that respond to stimuli from outside the body.

Proprioceptors

Receptors that respond to stretch in skeletal muscles and inform the brain about body position.

Nonencapsulated Receptors

Simple sensory receptors, often free nerve endings that respond to general sensations such as pain and temperature.

Encapsulated Dendritic Endings

More complex sensory receptors encased in connective tissue capsules, often mechanoreceptors.

Pain Tolerance

The level at which a person can tolerate pain; varies among individuals and is influenced by genetics.

Phantom Limb Pain

Pain perceived in a limb that has been amputated, often addressed with pain management techniques.

Peripheral Nerves

Cordlike organs of the PNS made of bundles of myelinated and nonmyelinated axons.

Epineurium

The tough fibrous sheath surrounding all fascicles in a nerve.

Regeneration of Nerve Fibers

The ability of peripheral axons to regenerate if the cell body is intact; does not occur in the CNS.

Wallerian Degeneration

The process by which axon fragments and myelin sheaths distal to injury degenerate.

Schwann Cells

Glial cells in the PNS that support the regeneration of damaged nerve fibers.