Chapter 13 - The Peripheral Nervous System

Flashcards covering key vocabulary terms and concepts related to the Peripheral Nervous System and Reflex Activity, as discussed in the lecture.

Peripheral Nervous System (PNS)

The part of the nervous system that encompasses all the nerves outside the brain and spinal cord.

Sensation

Awareness of changes in the external or internal environment (stimuli).

Perception

Conscious interpretation of stimuli.

Adaptation (in sensory terms)

A decrease in the responsiveness of a receptor, even though the stimulus is present.

Special Senses

Senses that have specialized organs for specific functions: Taste, Smell, Hearing, Vision, Equilibrium.

General Senses (Somatic Senses)

Senses that include touch, pain, pressure, vibration, and proprioception.

Mechanoreceptor

A type of sensory receptor that responds to mechanical pressure or distortion.

Thermoreceptor

A type of sensory receptor that responds to changes in temperature.

Photoreceptor

A type of sensory receptor that responds to light.

Chemoreceptor

A type of sensory receptor that responds to chemical stimuli.

Nociceptor

A sensory receptor that responds to pain.

Exteroceptor

A receptor that responds to external stimuli.

Interoceptor

A receptor that responds to internal stimuli.

Proprioceptor

A receptor that monitors the position and movement of body parts.

Nociceptors

Free nerve endings found in almost all tissues of the body that respond to pain.

Acute Pain

Pain that is short-term and usually related to a specific injury.

Chronic Pain

Long-lasting pain that can persist long after an injury.

Referred Pain

Pain that is perceived at a location other than the site of the painful stimulus.

Radiating Pain

Pain that spreads from the initial injury site to surrounding areas.

Cochlea

A spiral-shaped organ in the inner ear that is essential for hearing.

Pupil

The opening in the center of the eye that allows light to enter.

Lens

The transparent part of the eye that focuses light onto the retina.

Retina

The layer at the back of the eye that contains photoreceptors.

Optic Nerve

The nerve that transmits visual information from the retina to the brain.

Convergence (in vision)

The inward movement of both eyes toward each other to maintain single binocular vision.

Patellar Reflex

A knee-jerk reflex that is a type of stretch reflex.

Withdrawal Reflex

A reflex that pulls a body part away from a painful stimulus.

Crossed Extensor Reflex

A reflex that involves contraction of the extensor muscles on the opposite side of the body from the stimulus.

Cranial Nerves

Nerves that arise from the brain and are responsible for various sensory and motor functions.

Spinal Nerves

Nerves that arise from the spinal cord and innervate specific regions of the body.

Dermatome

An area of skin supplied by sensory fibers of a single spinal nerve.