Chapter 34: The Sensory System Flashcards

Vocabulary flashcards created from Chapter 34 notes covering the sensory system, eye and ear anatomy, vision and hearing disorders, and age-related changes.

Sensory System

The system that allows us to experience the world around us through sight, hearing, taste, smell, and touch, while helping protect us from harm.

Tactile Nerves

Nerves located in the skin responsible for perceiving touch.

Deep Touch Nerves

Nerves in the skin that sense pressure and prompt us to move positions.

Referred Pain

Radiating pain felt in a location different from the actual source of the pain, such as left arm pain during a heart attack.

Phantom Pain

A sensation of pain felt in a limb that has been amputated.

Tastebuds

Receptors located on the tongue responsible for detecting sweet, salty, bitter, sour, and umami tastes.

Umami

The savory taste flavor detected by tastebuds on the tongue.

Chemoreceptors

Sensory receptors for taste and smell in the nasal cavity and tongue that decrease with age, leading to reduced appetite.

Sclera

The tough outer layer of tissue of the eye, commonly known as the white of the eye.

Cornea

The clear part in the front of the eye that allows light to pass through.

Choroid

The middle layer of tissue in the eye containing blood vessels that supply nutrients.

Ciliary Body

Tiny muscles attached to the lens within the choroid layer that change the shape of the lens to allow the eye to focus.

Iris

The colored part of the eye that controls the amount of light entering through its central opening, the pupil.

Pupil

The opening in the center of the iris through which light enters the eye.

Retina

The innermost tissue layer of the eye containing rods and cones that convert light into nerve impulses.

Rods and Cones

Sensory receptors located in the retina that convert light into nerve impulses.

Optic Nerve

The nerve that transmits nerve impulses from the retina to the brain for visual interpretation.

Anterior Chamber

The fluid-filled chamber of the eye located between the cornea and the lens containing aqueous humor.

Aqueous Humor

The fluid contained within the anterior chamber of the eye.

Posterior Chamber

The fluid-filled chamber of the eye located between the lens and the retina containing vitreous humor.

Vitreous Humor

The fluid in the posterior chamber of the eye that gives the eyeball its shape.

Myopia

A vision defect commonly referred to as nearsightedness.

Hyperopia

A vision defect commonly referred to as farsightedness.

Astigmatism

A vision defect that causes blurred vision.

Presbyopia

An age-related condition where the eye lens becomes less flexible, preventing focus on close objects.

Conjunctivitis

Infection or inflammation of the conjunctiva, causing red sclera, itching, burning, excessive tearing, and sticky white or yellow discharge (pink eye).

Cataracts

Yellowing and hardening of the eye lens that prevents light from entering, leading to cloudy vision and potential blindness.

Glaucoma

An eye condition where pressure in the anterior chamber increases because aqueous humor is not properly absorbed, eventually destroying the retina.

Macular Degeneration

An eye condition caused by protein deposits or blood vessel development on the macula, damaging receptors and central vision.

Macula

The central part of the retina affected in macular degeneration where protein deposits or blood vessels build up.

Prosthetic Eye

A curved disc made of ceramic or plastic fitted underneath the eyelids to replace a missing eye.

Pinna

The outer ear structure, also known as the auricle, that collects sound waves and directs them down the canal to the eardrum.

External Auditory Canal

The passage in the outer ear lined with small hairs and glands that secretes cerumen to trap dirt and particles.

Cerumen

Earwax secreted by glands in the external auditory canal to protect the canal by trapping dirt and particles.

Tympanic Membrane

The eardrum, which separates the outer and middle ear and vibrates in response to sound waves.

Middle Ear

An air-filled space containing three tiny bones (ossicles) that forms a bridge between the eardrum and inner ear.

Ossicles

The three tiny bones in the middle ear consisting of the malleus, incus, and stapes.

Malleus

One of the three small auditory bones (ossicles) located in the middle ear.

Incus

One of the three small auditory bones (ossicles) located in the middle ear.

Stapes

One of the three small auditory bones (ossicles) located in the middle ear.

Eustachian Tube

A tube connecting the middle ear to the pharynx that equalizes pressure in the middle ear to prevent eardrum rupture.

Cochlea

A fluid-filled inner ear structure shaped like a snail shell that contains receptors for hearing.

Vestibular Apparatus

The inner ear structure, consisting of the vestibule and semicircular canals, that controls balance.

Vestibule

A part of the vestibular apparatus in the inner ear involved in maintaining balance.

Semicircular Canals

Passages within the vestibular apparatus of the inner ear responsible for balance control.

Cochlear Nerve

The nerve that carries nerve impulses generated in the cochlea to the brain for sound interpretation.

Motion Sickness

A condition caused by conflicting messages sent from the eyes and ears to the brain, resulting in nausea, dizziness, and vomiting.

Presbycusis

Age-related hearing loss characterized by the inability to hear high-pitched sounds and difficulty distinguishing sounds like th and s.

Otitis Media

An infection of the middle ear causing ear pain, fever, and difficulty hearing.

Otitis Externa

Infection of the lining of the external auditory canal, commonly called swimmer's ear, which is painful to touch.