A&P C9

Special Senses

Senses with specialized organs; vision, hearing, equilibrium (balance), taste, and smell

General Senses

Widely distributed receptors that detect touch, pressure, pain, temperature, and body position

How We Hear Sound

Sound waves enter the ear, vibrate the eardrum and ossicles, stimulate hair cells in the cochlea, and are interpreted by the brain

Divisions of the Ear

Outer ear, middle ear, inner ear

Outer Ear

Auricle (pinna) and external auditory canal; collects sound waves

Middle Ear

Contains eardrum and ossicles (malleus, incus, stapes); amplifies sound vibrations

Inner Ear

Contains cochlea and vestibular apparatus; hearing and balance

Ossicles

Malleus, incus, and stapes; smallest bones in the body

Cochlea

Spiral-shaped structure containing receptors for hearing

Eye Parts

Cornea, iris, pupil, lens, retina, optic nerve

Cornea

Clear front surface of eye; helps focus light

Iris

Colored part of eye; controls pupil size

Pupil

Opening that allows light into the eye

Lens

Focuses light onto the retina

Retina

Contains photoreceptors that detect light

Optic Nerve

Carries visual information to the brain

Tongue

Contains taste buds that detect different taste sensations

Taste Buds

Sensory receptors responsible for taste perception

Five Basic Tastes

Sweet, salty, sour, bitter, umami

Receptor Types

Chemoreceptors, photoreceptors, mechanoreceptors, thermoreceptors, nociceptors

Chemoreceptors

Detect chemicals; smell and taste

Photoreceptors

Detect light; vision

Mechanoreceptors

Detect pressure, touch, vibration, sound, and stretch

Thermoreceptors

Detect temperature changes

Nociceptors

Detect pain and tissue damage

Color Blindness

Inability to distinguish certain colors due to missing or defective cone cells in the retina

Cones

Photoreceptors responsible for color vision and detailed vision

Rods

Photoreceptors responsible for night vision and peripheral vision

Most Common Color Blindness

Red-green color blindness