eye, ans, cortex
Terms
undefined, object
copy deck
- bones of the orbit
-
frontal
lacrimal
presphenoid
palatine
zygomatic - The gap bt the margins of the two palpebrae is the
- palpebral fissure
- main muscles of the eyelids
-
m. orbicularis oculi
m. levator palpebrae superioris - The palpebrae are afforded a certain amount of rigidity by the presence of a layer of dense fibrous connective tissue within them, the ______ ______
- tarsal plate
-
Which of the animals listed below have cilia on the palpebra superior and inferior; which have only superior cilia; and which have no cilia on the eyelids
dogs, cats, horses, cattle, pigs, and sheep. -
Herbivors: have both
Dogs: only superior
cats:none - The _______ glands of the eye produce the oil layer of the tear film
- tarsal
- The __________ is the mucous membrane that lines the inside of the eyelids and the surface of the eyeball(excluding the clear cornea).
- conjunctiva
- The conjunctiva on the deep side of the palpebrae is identified as __________ _________. Where it approaches the edge of the orbit, the conjunctiva reflects back onto the surface of the eyeball and is called __________ _______. The angle made by this ref
-
palpebral conjunctiva
bulbar conjunctiva
conjunctival fornix
conjunctival sac - nictitating membrane
- third eyelid
- Third eyelid is given rigidity by a ________ _______, and it functions to smooth the _________ ________ _______, to produce a portion of the _________ ________ _______, and to protect the ________
-
T-shaped cartilage
precorneal tear film
precorneal tear film
cornea - "cherry eye"
- prolapse of the gland of the third eyelid
- The lacrimal gland receives sensory innervation from the _______ nerve a branch of the _________ nerve. and its parasympathetic motor innervation originates in the ________ nerve a branch of the __________ nerve. Parasympathetic preganglionic neurons syn
-
lacrimal
ophthalmic
major petrosal
pterygopalatine - layers of the precorneal tear film
-
outer oil layer: tarsal glands
Aqueous layer: lacrimal and gland of the third eyelid
mucoid layer:conjuctiva's goblet cells - The ________ ________ are linear accumulations of mucus normally found in the superior and inferior fornices
- mucous threads
- As the precorneal tear film is produced, it accumulates in the inferior conjunctival fornix where it forms the _________ ______
- lacrimal lake
- drooping of the upper eyelid
- ptosis
- The superior palpebral levator muscle is innervated by the ________ nerve
- oculomotor
- forward displacement of the eye
- exophthalmos
- sinking of the eye
- enophthalmos
- adipose tissue behind the eyeball
- retrobulbar fat
- 3 tunics of the eyeball
-
fibrous tunic
vascular tunic
nervous tunic - acellular gel in the posterior globe
- vitreous body
- The sclera meets the clear cornea at a transitional region called the _________
- limbus
- where optic nerve leaves the globe
- area cribrosa
- highly vascular outer layer of the sclera
- episclera
- corneal transparency is a function of what 5 things
-
1.lack of vascular elements and cells
2.lack of pigment
3.relative dehydration of the tissue
4.smooth optical surface
5. highly regular laminar pattern of collagen fibers that reduces light scatter - 5 layers of the cornea
-
1.precorneal tear film
2.anterior epithelium and its basement membrane
3.stroma
4.Descemet's membrane
5.endothelium - In corneal injuries that penetrate the full thickness of the stroma, Descemet's membrane may bulge through the defect and form a blister in the injury site. This ___________ is a sign of a cornea that is about to rupture and constitutes an ocular emergen
- descemetocele
- Sources of oxygen and nutrients for the cornea
-
1.fluid within the anterior chamber
2.precorneal tear film
3. capillaries at the limbus - The vascular tunic or _______ is composed of 3 parts the _______, _________, and ________
-
uvea
choroid
ciliary body
iris - The reflective portion of the choroid which bounces photons back onto the retina
- tapetum
- The tapetum is located on the _______ portion of the posterior globe.
- dorsal
- The ___________ is the anterior continuation of the uvea and lies immediately posterior to the iris. It gives rise to fingerlike _________ to which the lens is attached by __________.
-
ciliary body
ciliary processes
suspensory ligaments - The process of focusing on nearer objects is called
- accommodation
- What produces aqueous humor?
- capillaries of the ciliary body
-
parts of eye -
parts of eye - production of aqueous humor requires the enzyme __________
- carbonic anhydrase
- The _____ is the most anterior portion of the uvea and the only part of the vascular tunic normally visible in the living animal.
- iris
- constiction of the pupil
- miosis
- innervation pathway to constrict the pupil
- oculomotor nucleus > oculomotor n. > ciliary ganglion > short ciliary nn.> m. constrictor pupillae
- innervation pathway to dilate the pupil
- preganglionic in lateral column of spinal cord segments T1-2/3 > vagosympathetic trunk > cranial cervical ganglion > sympathetic post ganglion fibers > m. dilator pupillae
- dilation of the pupil
- mydriasis
- In herbivors (esp horses) the pigmented epithelium of the posterior surface of the iris together with tissue of the iridial stroma forms nodular masses along the margin of the pupil called
- corpora nigra
- when pupillary membrane fails to atrophy during development
- persistent pupillary membranes
- The region of the anterior chamber where the iris and the sclera approach one another is bridged by a series of fine fibers collectively known as _______________. Deep to these ligaments is the _____________, a labyrinthine set of passages
-
pectinate ligaments
trabecular meshwork - increased intraocular pressure
- glaucoma
- The deepest layer of the eyeball is the nervous tunic or ______
- retina
- The retina is divided into 3 parts the __________________ is a simple pigmented epithelium attached to the posterior surface of the iris. The retina then reflects over the surface of the ciliary body, being called here _______________. Finally the light
-
pars iridca retina
pars ciliaris retina
pars optica retinae - vision in dim light
- scotopic
- layers of the retina
-
1.pigment epithelium
2.photoreceptor layer
3.bipolar cells
4.ganglion cell layer
5. nerve fiber layer - area that receives light from the center of the visual field
- area centralis
- Components of the fundus
- tapetum, the nontapetal area, optic disk, and retinal vasculature
- Carnivores and ruminants exhibit a ___________ retinal vascular pattern while horses have __________ vascular pattern
-
holangiotic
paurangiotic - stars of winslow
- red or darik dots repersenting end on capillaries in the equine tapetal region
- 3 routes of venous return from the globe
-
1.angular vein
2.ophthalmic plexus
3.ventral external ophthalmic vein - lenticular sclerosis
- As the animal ages more lens fibers are added to the cortex, compressing the fibers at the lens' center. these old cells become hardened and after middle age begin to lose their transparency
- transparent media that serve to refract and focus light on retina
-
dioptric media:
1.cornea
2.aqueous humor
3.lens
4.vitreous body