Chapter 15 Eye Anatomy Flashcards
Eye Anatomy
Protect and aid in function of eye
Include: eyebrows, eyelids, conjunctiva, lacrimal apparatus, extrinsic eye muscles
Accessory structures
70% of body’s sensory receptors located here
Half of cerebral cortex is involved in visual processing
Small sphere; only 1/6th is seen
Features: accessory structures, eyeball
Eye
Overlie supraorbital margins
Function: shade eye from sunlight, prevent perspiration from reaching eye
Eyebrows
A.k.a. palpebrae
Thin, skin covered folds that protect eye anteriorly
Separated at palpebral fissure
Meet in corners at medial and lateral commissures
Eyelids
Project from eyelids
Follicles of eyelash hairs are innervated
When eyelashes touched it triggers reflex blinking
Eyelashes
Located at medial commissure; contains oil and sweat glands
Lacrimal caruncle
Part of eyelid; Supporting connective tissue that give eyelids shape; has “plates” that anchor orbicularis oculi and levator palpebrae superioris muscles
Tarsal plates
Modified sebaceous glands that produce oily secretion that lubricates lid and eye
Tarsal glands
Infected tarsal gland, creates a cyst called _______
Chalazion
Inflammation of any of the smaller sebaceous gland
Stye
Transparent mucous membrane that produces a lubricating mucus secretion
3 parts: Palpebral, bulbar, conjunctival sac
Conjunctiva
Membrane that lines underside of eyelids
Palpebral conjunctiva
Membrane that covers white of eyes; small blood vessels found here
Bulbar conjunctiva
Space between palpebral and bulbar conjunctiva; where contact lens sit
Conjunctival sac
Inflammation of the conjunctiva resulting in reddened, irritated eyes
Conjunctivitis
Turns eye pink
Conjunctival infection caused by bacteria or viruses
Pink eye
Located in orbit above lateral end of eye; Secretes lacrimal secretions (tears)
Lacrimal gland
Where tears drain into; ______ then ________
Lacrimal sac
Nasolacrimal duct
6 straplike muscles that originate in the bony orbit and insert into eyeball
Enable eye to follow moving objects, maintain shape, and hold it in orbit
Extrinsic eye muscles
1. Lateral rectus
2. Medial rectus
3. Superior rectus
4. Inferior rectus
5. Inferior oblique
6. Superior oblique
Moves eye laterally
Lateral rectus
Moves eye medially
Medial rectus
Elevates eye and turns it medially
Superior rectus
Depresses eye and turns it medially
Inferior rectus
Elevates eye and turns it laterally
Originates from medial surface and inserts on inferolateral part of eye
Inferior oblique
Depresses eye and turns it laterally
Originates at common tendinous ring then passes through fibrocartilage loop (trochlea) and inserts in superolateral part of eye
Superior oblique
Occurs when movements of external muscles of two eyes are not perfectly coordinated
Ex. Seeing two images instead of one
Diplopia