Overview of Sensory Receptors and the Eye

Sensory receptor

A sensory receptor is a structure that functions to receive sensory stimuli and generate an electrical neuronal signal.

Exteroceptors

Exteroceptors are receptors that receive stimuli from the external environment.

Interoreceptors

Interoreceptors are receptors that receive stimuli from the internal environment (like organs).

Proprioceptors

Proprioceptors receive information about the relative stretch of muscles and tendons in order to understand where the body parts are in space.

Thermoreceptor

A type of sensory receptor that responds to temperature changes.

Photoreceptor

A type of sensory receptor that responds to light.

Chemoreceptor

A type of sensory receptor that responds to chemical stimuli.

Baroreceptor

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

Nociceptor

A type of sensory receptor that responds to pain stimuli.

Mechanoreceptor

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

General sense receptor

A type of sensory receptor that detects general sensations such as pain, temperature, and touch.

Special sense receptor

A type of sensory receptor that is specialized for specific senses such as vision, hearing, taste, and smell.

Tactile receptor

Receptors that respond to touch and pressure, including tactile (Merkel) discs and lamellated (Pacinian) corpuscles.

Olfactory epithelium

The tissue in the nasal cavity that contains olfactory receptor cells responsible for the sense of smell.

Olfactory receptor cell

A type of sensory receptor cell that detects odor molecules.

Taste buds

Structures on the tongue that contain gustatory receptor cells responsible for the sense of taste.

Gustatory receptor cell

A type of sensory receptor cell that detects taste stimuli.

Cranial nerves for taste

Nerves that transmit taste information from the tongue to the brain.

Outer ear

The external part of the ear that collects sound waves.

Middle ear

The cavity that contains the ossicles and transmits sound vibrations to the inner ear.

Inner ear

The part of the ear that contains the cochlea and vestibular system, responsible for hearing and balance.

Cochlea

A spiral-shaped structure in the inner ear that contains the sensory organ for hearing.

Spiral organ (of Corti)

The sensory structure within the cochlea that contains hair cells responsible for converting sound vibrations into nerve impulses.

Scala vestibuli

The vestibular duct of the cochlea that conducts sound waves.

Scala tympani

The tympanic duct of the cochlea that conducts sound waves.

Thermoreceptors

temperature receptors

Photoreceptors

receive photons of light

Chemoreceptors

bind chemicals

Baroreceptors

detect pressure changes

Nociceptors

pain receptors

Mechanoreceptors

detect touch, vibration, stretch, etc

General senses

all over the body

Special senses

limited to the head

General senses

dendritic ends of neurons

Special senses

dedicated specialized receptor cells

General senses

touch, pain, vibration, stretch, itch

Special senses

smell, equilibrium, hearing, vision, taste

Tactile receptors

e.g., tactile [Merkel] disc and lamellated [Pacinian] corpuscle

Tears

produced for crying

Pupil

widens or narrows in response to light availability

Sympathetic nervous system

widens the pupil

Anterior and posterior cavities of the eye

associated with humors

Lens

role in vision

Retina components

e.g., optic disc, macula lutea, fovea centralis, rods, cones

Path of light

passes through the eye to the retina, refracted by structures

Rods and cones

functions and locations

Olfactory epithelium

location and structure

Path of olfaction

from olfactory receptors to the brain

Taste buds

location and structure

Cranial nerves

transmit taste information from the tongue to the brain

External ear structures

e.g., elastic cartilage

Middle ear structures

identify components

Inner ear components

Vestibule, Semicircular canals, Cochlea

Auditory processing

occurs in the temporal lobe