1. Chapter 14

2. Ocular System Eye: structure for sight Extraocular: outside the eye
Intraocular: inside the eye
Periocular: around the eye

3. Ocular Accessories (Adnexa/Stroma)
Orbit: bony cavity of skull, eye held here
Eye muscles: work together for Binocular
7 major muscles per eye
2 oblique, 4 rectus, retractor bulbi
6 Extrinsic muscles provide attachment
Eyelids, Canthus (angle where eyelids meet), Tarsal plate (upper n lower eyelids), Meibomian glands, eyelashes, conjuctiva (mucous membrane that lines under side of each eyelid), Lacrimal apparatus (produce/store/ remove tears)

4. Eyeball / Globe Sclera: fibrous outer layer of eye (white of the eye)
Anterior portion = cornea
Choroid: opaque middle layer of the eye (not light passage)
Pupil : Central circular opening
Lens: clear flexible curved capsule located behind the iris and pupil, Adjusts (accommodates) to see near/far
Ciliary Body: thickened extension of choroid to aid in accommodation
Iris: “Colored portion”, contains muscles that contract pupil in response to light

5. Eye Contin:
Retina: nerve tissue layer that receives images

6. Canine Eye

7. Vision Accommodation: Distance
Refraction: Lens bends rays of light to help focus
Convergence: simultaneous inward movement in both eyes, normally happens as an object moves closer
Acuity: sharpness of vision

8. Common Tests: Eyes
PLR: pupillary light reflex: animal’s response to light
Flourescein: dye on the surface to detect corneal injury
Menace Response: eye should close as object moves towards it
Palpebral reflex: blink in response to eye being touched
Schirmer tear test: graded paper slip measures tear production

9. Common Ailments: Anisocoria: unequal pupil size
Blepharitis: inflammation of eyelid
Blepharoptosis: dropping of eyelid
Cataract: cloudiness of eye
Entropin: inturning of eyelid
Strabismus: “cross eyed”

10. Common Procedures: Eyes
Common prefixes
Oplasty: surgical repair
Ectomy: removal
Otomy: incision
Centesis: removal of liquid (to relieve pressure)

11. EARS: Structures Outer Ear Middle Ear
Pinna: external portion that catches sounds waves
Middle Ear
Eardrum: tissue separating external from middle ear
Auditory ossicles: ear bones
Malleus, incus, stapes
Eustachin tubes
Oval window: separates middle from inner ear
Round window: membrane receives sound waves
Tympanic bulla: located at base of skull

12. EAR Structures Continued:
Inner Ear