Physiology 261 – Chapter 10: Sensory Physiology Vocabulary

A comprehensive set of vocabulary flashcards covering key terms and concepts from Chapter 10 on sensory physiology.

Special senses

Vision, hearing, taste, smell, and equilibrium.

Somatic senses

Touch, temperature, pain, itch, and proprioception.

Chemoreceptors

Sensory receptors most sensitive to chemical stimuli.

Mechanoreceptors

Receptors that respond best to mechanical forces such as pressure or vibration.

Thermoreceptors

Receptors specialized for sensing temperature changes.

Photoreceptors

Light-sensitive receptors found in the eye’s retina.

Adequate stimulus

The specific form of energy to which a receptor is most responsive.

Graded potential (receptor potential)

Electrical change produced in a sensory receptor when a stimulus is above threshold.

Receptive field

The region in which a stimulus can activate a particular sensory neuron.

Thalamus

Brain structure that relays most sensory information to cerebral cortex (except olfaction).

Perceptual threshold

Minimum stimulus intensity needed for conscious awareness.

Label line coding

Association of a specific receptor with a particular sensation or modality.

Lateral inhibition

Process that enhances contrast between center and edges of a receptive field.

Population coding

Use of input from multiple receptors to determine location and timing of a stimulus.

Tonic receptor

Slowly adapting receptor that fires as long as stimulus persists.

Phasic receptor

Rapidly adapting receptor that responds to changes in stimulus intensity.

Somatosensory modalities

Touch, proprioception, temperature, and nociception.

Nociceptor

Free nerve ending that detects painful or itch-inducing stimuli.

A-delta fibers

Small, myelinated axons that carry fast, sharp pain.

C fibers

Small, unmyelinated axons that convey slow, dull pain.

Referred pain

Perception of visceral pain in a superficial body region due to converging pathways.

Neuropathic pain (chronic pain)

Pathological pain that persists after tissue damage has healed.

Olfaction

Sense of smell mediated by bipolar olfactory neurons projecting to olfactory cortex.

Gustation

Sense of taste comprising sweet, sour, salty, bitter, and umami.

Taste cells

Non-neural epithelial cells that release neurotransmitter onto primary gustatory neurons.

Hearing

Perception of energy carried by sound waves converted to electrical signals.

Organ of Corti

Sensory structure in cochlear duct containing hair-cell receptors for sound.

Hair cell (ear)

Mechanoreceptor that depolarizes when its stereocilia bend.

Auditory ossicles

Malleus, incus, and stapes; bones that amplify vibrations to the oval window.

Pitch processing

Initial coding of frequency of sound within the cochlea.

Vestibular apparatus

Inner-ear structure housing receptors for equilibrium and linear acceleration.

Semicircular canals

Three fluid-filled loops that detect rotational acceleration.

Vision

Translation of reflected light into a mental image via retinal photoreceptors.

Pupil

Opening in the iris that regulates the amount of light entering the eye.

Ciliary muscle

Muscle that alters lens shape to focus light.

Fovea

Retinal region with highest visual acuity and smallest receptive fields.

Rods

Photoreceptors responsible for monochromatic, low-light vision.

Cones

Photoreceptors responsible for color and high-acuity daytime vision.

Rhodopsin

Visual pigment in rods composed of opsin protein and retinal chromophore.

Opsin

Protein component of rhodopsin to which retinal binds.

20⁄20 vision

Ability to see at 20 ft what a person with normal sight sees at 20 ft.

Two-point discrimination test

Clinical method to map receptive field density on skin.

Equilibrium (balance)

Sense mediated by vestibular hair cells detecting gravity and acceleration.

Population frequency coding

Intensity coding via number of receptors firing and their action-potential rate.

Oval window

Membranous interface where stapes transfers vibrations into cochlear fluids.

Medulla–midbrain–thalamus–auditory cortex pathway

Ascending neural route for sound information to reach perceptual centers.