Chapter 34 sensory system study guide

Tactile nerves

Nerves found primarily in the skin, especially in sensitive areas like fingertips, palms, and soles of the feet.

Deep touch nerves

Nerves that help us sense pressure and signal the body to move position.

Referred pain

Pain felt in one part of the body resulting from another area; for example, pain from a heart attack felt in the arm.

Phantom pain

Sensation of pain in an amputated limb.

Taste buds

Sensory receptors located in the tongue responsible for taste.

Chemoreceptors (smell)

Sensory receptors located in the nasal cavity responsible for detecting odors.

Age-related changes in chemoreceptors

Decrease in the number of chemoreceptors, resulting in less intense taste and smell, and decreased appetite.

Three layers of the eye

Sclera, choroid, retina.

Sclera

The white part of the eye.

Cornea

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

Choroid layer of the eye

The middle layer that supplies nutrients to the eye.

Ciliary body

Tiny muscles attached to the lens of the eye that help control its shape.

Iris

The colored part of the eye that controls the amount of light entering.

Retina

The innermost layer of the eye that contains receptors (rods and cones).

Anterior chamber

The fluid-filled chamber in the eye between the cornea and the lens, containing aqueous humor.

Posterior chamber

The fluid-filled chamber in the eye between the lens and retina, containing vitreous humor.

Myopia

A condition of nearsightedness.

Hyperopia

A condition of farsightedness.

Astigmatism

A condition that results in blurred vision due to an irregular shape of the cornea or lens.

Decreased receptors in the retina with age

A reduction in the number of cones and rods in the retina as a person ages.

Presbyopia

A condition in which the lens becomes less flexible, making it difficult to focus on close objects.

Decreased tear production

Age-related change in the eye that can cause dryness and irritation.

Conjunctivitis

Also known as pink eye, it is an infection or inflammation of the conjunctiva, causing redness, itching, burning, and discharge.

Cataracts

Condition characterized by yellowing and hardening of the lens, leading to cloudy vision.

Glaucoma

A condition caused by increased pressure in the anterior chamber of the eye, which can lead to damage of the retina.

Macular degeneration

A disease where protein deposits or blood vessels develop on the macula, affecting central vision.

Care for cataracts, glaucoma, or macular degeneration patients

Adjust care strategies based on the specific conditions affecting their vision.

Cleaning eyeglasses

Should be done with special solutions and soft cloths to prevent scratches.

Storing contact lenses

Important to place them correctly and ensure they are cleaned properly to avoid confusion.

Prosthetic eyes materials and shape

Typically made of ceramic or plastic.

Handling prosthetic eyes with care

They are expensive and can cause injuries or irritation if mishandled.

Three main parts of the ear

Outer ear, middle ear, inner ear.

Function of the pinna (auricle)

Collects sound waves and directs them down the ear canal.

External auditory canal secretion

Secretes cerumen (earwax) to trap dirt and protect the canal.

Function of the tympanic membrane (eardrum)

Vibrates in response to sound waves, separating the outer and middle ear.

Middle ear ossicles

The three tiny bones: malleus, incus, and stapes, that amplify sound vibrations.

Function of the eustachian tube

Connects the middle ear to the pharynx and equalizes pressure.

Cochlea

A spiraled structure in the inner ear filled with fluid that converts sound vibrations into electrical signals.

Structures for balance in the inner ear

Vestibule and semicircular canals.

Sound path from pinna to brain

Sound travels through the pinna, down the auditory canal, vibrates the tympanic membrane, passes through the ossicles, enters the cochlea, and is sent to the brain via the auditory nerve.

Vestibular apparatus sensors

Help maintain balance by detecting head position and motion.

Causes of motion sickness

Conflicting messages from the eyes and inner ears send conflicting signals to the brain.

Presbycusis

A condition resulting in the loss of ability to hear high-pitched sounds.

Cerumen (earwax) buildup risks

Can lead to decreased hearing, fullness, ringing, itching, and pain.

Increased risk factors for cerumen impaction

Age, ear canal anatomy, use of earplugs, attempts to remove earwax, and skin conditions.

Otitis media

Middle ear infection characterized by ear pain, fever, and difficulty hearing.

Otitis externa (swimmer's ear)

Infection of the external auditory canal that is painful to touch.

Meniere's disease

An inner ear disorder that causes episodes of vertigo, tinnitus, and temporary hearing loss.

Guidelines for communicating with hearing-impaired individuals

Face the person, avoid chewing gum, speak clearly, use a notepad, and ensure understanding.

Troubleshooting hearing aids

Check the batteries and ensure the ear canal is not blocked with cerumen.