Peripheral Nervous System Overview

A comprehensive set of flashcards covering key concepts related to the Peripheral Nervous System, its divisions, structures, types of fibers, and nerve regeneration.

Peripheral Nervous System (PNS)

The part of the nervous system that is outside the brain and spinal cord, consisting of sensory and motor divisions.

Sensory (afferent) division

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

Motor (efferent) division

The division of the PNS responsible for transmitting signals from the CNS to effectors like muscles and glands.

Somatic nervous system

The part of the motor division that controls voluntary movements by sending impulses to skeletal muscles.

Autonomic nervous system (ANS)

The part of the motor division that regulates involuntary functions, divided into sympathetic and parasympathetic divisions.

Mechanoreceptors

Receptors that respond to mechanical stimuli like touch, pressure, vibration, and stretch.

Thermoreceptors

Receptors that respond to changes in temperature.

Photoreceptors

Receptors that respond to light energy, primarily located in the retina.

Chemoreceptors

Receptors that respond to chemical changes, such as smell and taste.

Nociceptors

Receptors that are sensitive to pain-inducing stimuli, such as extreme temperatures and inflammatory chemicals.

Axon

A long projection of a neuron that conducts electrical impulses away from the neuron's cell body.

Myelin sheath

A protective layer that surrounds many axons, enabling faster transmission of electrical impulses.

Endoneurium

The connective tissue sheath that surrounds individual nerve fibers (axons).

Perineurium

The connective tissue sheath that encases a bundle of nerve fibers (fascicle).

Epineurium

The outermost layer of connective tissue that surrounds the entire nerve, including all fascicles.

Mixed nerves

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

Somatic afferent fibers

Fibers that transmit sensory impulses from the skin, muscles, and joints to the CNS.

Somatic efferent fibers

Fibers that transmit motor impulses from the CNS to skeletal muscles.

Visceral afferent fibers

Fibers that carry sensory impulses from internal organs to the CNS.

Visceral efferent fibers

Fibers that transmit motor impulses from the CNS to autonomic targets.

Regeneration of Nerve Fibers

The ability of PNS nerve fibers to regenerate if the soma is intact; CNS fibers generally do not regenerate due to inhibiting factors.