Veterinary Science: Anatomy and Physiology; Section 11 Eye & Ear
Order by
56 terms
Terms | Definitions |
|---|---|
 Two major functions of the ear | hearing and balance. |
| Process of hearing | sound vibrations are transformed into a nervous impulse & transmitted to the brain by the auditory nerve. |
| Auditory nerve | cranial nerve VIII. |
| Process of balance | nerve endings in the ear sense changes in position of the head. |
| Three parts of the ear | external, middle, inner. |
| Pinna | funnel-shaped, made of skin and cartilage. narrow down to ear canal. |
| Ear canal is common for... | ear mites, and infections. |
| Tympanic membrane | ear drum. separates external ear from middle ear. |
| Tympanic bulla | middle ear. hollow chamber. |
| Eustachian tube | connects the pharynx to the middle ear. |
| Bones of the ear and function | hammer, anvil, stirrup. vibrate when noises heard. |
| Inner ear found in the... | petrous temporal bone. |
| Two parts of the inner ear and functions of each | Cochlear (hearing), vestibular (balance). |
| Cochlea | Snail-shaped, filled with fluid. |
| Organs of corti | Structures on the cochlea projecting outward, has cilia. |
| Deafness can be due to... | sound wave conduction problems, inflammation, injury, obstruction or nerve problem. |
| Equilibrium controlled in... | three semicircular canals oriented in three planes (transverse, horizontal, vertical), that contain fluid with small crystals. |
| Problems with the three semicircular canals | Vertigo (Dizziness), motion sickness, nystagmus. |
| Nystagmus | Rapid back-and-forth eye movement. |
| External layer of eye | Fibrous coat containing the cornea and sclera. |
| Cornea | Clear, anterior part of eye. Has nerves. |
| Sclera | White posterior part of eye; dense and opaque. Has blood vessels and nerves. Muscle attach to it. |
| Limbus | Area where cornea and sclera meet. |
| Optic nerve | Cranial Nerve II connected to back of eye. |
| Iris | Pigmented portion of eye. Ring of muscle that opens or closes to control amount of light let in. |
| Pupil | "Pupillary opening." Opening of the iris. Round in most species, elliptical in cats and snakes. |
| Lens | Behind iris. Biconvex, transparent, and elastic. |
| Cataract | Cloudy lens. |
| Vitreous chamber | Behind the lens, filled with vitreous humor, gelatinous. |
| Aqueous humor | In front of the lens, watery. |
| Anterior chamber | In front of iris. |
| Posterior chamber | Behind iris. |
| Glaucoma, and use what to measure | Aqueous humor made quicker than it can exit eye. Increased pressure. Use tonometer to measure pressure. |
| Ciliary body | Muscle that contracts to make lens thinner, and relaxes to make lens thicker. |
| Accommodation | Bending of light to focus on retina. Distance = thinner, Closer = thicker. |
| Retina | Used to see, 10 nervous tissue layers thick, picks up light and transmits it to brain down optic nerve, contains pigment. |
| Tapetum | Reflective part of retina, eye glows. |
| Optic disc | Where nerves in the retina join. Where optic nerve links eye to brain. |
| Fundus | Back of the eye where retina and optic nerve can be seen. |
| Ophthalmoscope | Used to examine eye. |
| Photoreceptors in eye | Rods and cones. |
| Rods | Cells very sensitive to light. |
| Cones | Cells used for detail and color perception. |
| Palpebra and function | Eyelids. Keep eye from drying out, make lubrication in glands in corner of eye. |
| Conjunctiva | Mucous membrane lining of eye. |
| Canthus | Corner of the eye. Medial and lateral. |
| Nictitating membrane | Third eyelid. |
| Cherry eye and common in... | Tear in gland attached to third eyelid, sticks out. Common in cocker spaniels. |
| Lacrimal glands | Tear glands found in dorso-lateral eye. |
| Function of tears | Wash away debris, lubricate, keep cornea moist. |
| Nasolacrimal ducts | "Puncta." Two small openings that drain fluid at the medial canthus. |
| Conjunctivitis | Inflammation/infection of the conjunctiva. Common in animals with URTI. |
| Ossicles | Bones in the ear. |
| Malleus | Hammer. |
| Incus | Anvil. |
| Stapes | Stirrup. |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.