Special Senses: The Eyes and Ears

blephar/o

eyelid

-cusis

hearing

irid/o

iris, colored part of the eye

kerat/o

horny, hard, cornea

myring/o

tympanic mebrane, eardrum

ophthalm/o

eye, vision

-opia

vision condition

opt/o

eye, vision

ot/o

ear, hearing

phak/o

lens of eye

presby/o

old age

retin/o

retina, net

scler/o

sclera, white of eye, hard

trop/o

turn, change

tympan/o

tympanic membrane, eardrum

Adnexa of the eyes

AKA adnexa oculi, are the structures outside the eyeball.

Adnexa

Accessory or adjoining anatomical parts of an organ.

Orbit

AKA eye socket, is th ebony cavity of the skull that contains and protects the eyeball and its associated muscles, blood vessels, and nerves.

Major eye muscles

• Superior and inferior oblique muscles

• Superior and inferior rectus muscles

• Lateral and medial rectus muscles

Binocular vision

Occurs when the muscles of both eyes work together in coordination to make normal depth perception possible.

Depth perception

Ability to see things in three dimensions.

Canthus

Angle where the upper and lower eyelids meet.

canth

Corner of the eye

Cilia

Small hairs, make up the eyebrows and eyelashes.

Tarsus

AKA tarsal plate, is the framework within the upper and lower eyelids that provides the necessary stiffness and shape.

tars

Edge of the eyelid

Conjunctiva

Transparent mucous membrane that lines the underside of each eyelids and continues to form a protective covering over the exposed surface of the eyeball.

Lacrimal apparatus

AKA tear apparatus, consists of the structures that produce, store, and remove tears.

Lacrimal glands

Secrete lacrimal fluid (tears), are located on the underside of the upper eyelid just above the outer corner of each eye.

Lacrimal fluid

AKA tears, maintains moisture on the anterior surfave of the eyeball.

Lacrimal canal

Consists of a duct at the inner corner of each eye.

Lacrimal sac

AKA tear sac, is an enlargement of the upper portion of the lacrimal duct.

Lacrimal duct

AKA nasolacrimal duct, is the passageway that drains excess tears into the nose.

Eyeball

AKA globe, is a 1-inch sphere with only about one-sixth of its surfave visible.

Optic

Pertaining to the eye or sight

Ocular

Pertaining to the eye

Extraocular

Outside the eyeball

extra-

outside

Intraocular

Within the eyeball

Sclera

AKA white of the eye, maintains the shape of the eye and protects the delicate inner layers of the tissue.

Choroid

AKA choroid coat, is the opaque middle layer of the eyeball that contains many blood vessels and provides the blood supply fpr the entire eye.

Retina

Sensitive innermost layer that ines the posterior segment of the eye.

Aqueous humor

AKA aqueous fluid, fills both of these chambers.

aqueous

Watery or containing water.

Humor (in aqueous humor)

Clear body liquid or smifluid substance.

Intraocular Pressure (IOP)

Measurement of the fluid pressure inside the eye.

IOP

Intraocular Pressure

Posterior segment

Makes up the remaining two-thirds of the eyeball, is lines with the retina and filled with vitreous humor.

Viterous humor

AKA vitreous gel, this is a soft, clear, jelly-like mass that contains millions of fine fibers.

What do the rods and cones of the retina recieve?

Images thats have passed through the lens of the eye.

What color are the Rods of the retina?

Black and white receptors

What color are the Cones of the retina?

Color receptors

Macula

AKA macula lutea, is the clearly defined light-sensitive area in the center of the retina that is responsible for sharp central vision.

Fovea centralis

A pit in the middle of the macula.

Optic disk

AKA blind spot, is. a small region in the eye where the nerve endings of the retina enter the optic nerve.

Optic nerve

Transmits these nerve impulses from the retina to the brain.

Uvea

Pigmented layer of the eye.

Ciliary body

Located within the choroid, is a set of muscles and suspensory ligaments that adjust the thickness of the lens to refine the focus of light rays on the retina.

Iris

Colorful circular structure that surrounds the pupil.

Cornea

Transparent outer furface of the eye covering the iris and the pupil.

Pupil

Black circular opening in the center of the iris that permits light to enter the eye.

Lens

Clear, flexible, curved structure that focuses images on the retina.

Accommodation

Process whereby the eyes make adjustments for seeing objects at various distances.

Convergence

Simultaneous inward movement of the eyes toward each other.

Emmetropia

Normal relationship between the refractive power of the eye and the shape of the eye that enables light rays to focus correctly on the retina.

Refraction

AKA refractive power, is the ability of the lends to bend light rays so they focus on the retina.

Visual acuity (VA)

The ability to distinguish object details and shape at a distance.

Acuity

Sharpness

VA

Visual Acuity

Ophthalmologist

Physician who specializes in diagnosing and treating the full spectrum of diseases and disorders of the eyes, from vision correction to eye surgery.

Optometrist

Holds a doctor of optometry degree and provides primary eye care, including diagnosing eye diseases and conditions, and measuring the accuracy of vision to determine whether corrective lenses are needed.

Optician

Health care practitioner who designs, fits, and dispenses lenses for vision correction.

Ptosis

Drooping of the upper eyelid that is usually due to muscle weakness or paralysis.

Chalazion

A nodule or cyst, usually on the upper eyelid, caused by obstruction of a sebaceous gland.

Hordeolum

AKA stye, pus-filled and often painful lesion on the eyelid resulting from an acute infection in a sebaceous gland.

Blepharitis

Swelling of the eyelid, often at the location of the eyelash hair follicles.

Ectropion

Everison of the edge of an eyelid.

Eversion

Turning outward.

Entropion

Inversion of the edge of an eyelid.

Inversion

Turning inward.

Periorbital edema

Swelling of the tissues surrounding the eye or eyes.

Conjuctivitis

AKA pinkeye, an inflammation of the conjunctiva that is usually caused bu a viral infection, allergy, or irritants.

Dacryoadenitis

An inflammation of the lacrimal gland caused by a bacterial, viral, or fungal infection,

Dacryocystitis

Inflammation of the lacrimal sac usually caused by blockage of the lacrimal duct, often accompanied by a bacterial infection.

Subconjunctival hemorrhage

Bleeding between the conjunctiva and the selera.

Xerophthalmia

AKA dry eye, is drying of eye surfaces, including the conjunctiva, because the tear glands do not produce enough tears.

xer

dry

Uveitis

Inflammation of the uvea causing swelling and irritation.

Iritis

Most common form of uveitis.

Corneal abrasion

An injury, such as a scratch or irritation, to the outer layers of the cornea.

Corneal ulcer

Open sore on the cornea caused by an infection or injury.

Keratitis

Inflammation of the cornea.

Keratoconus

Occurs when the cornea becomes irregular and cone-shaped, causing blurring and distortion of vision.

Scleritis

Inflammation of the sclera.

Anisocoria

Condition in which the pupils are unequal in size.

anis/o

unequal

Cataract

Loss of transparency of the lens that causes a progressive loss of visual clarity.

Diabetic retinopathy

Damage to the retina as a complication of uncontrolled diabetes.

Endophthalmitis

Inflammation of the intraocular fluids.

Floaters

AKA vitreous floaters, are particles of cellular debris that float in the vitreous humor and cast shadows on the retina.