Shared Flashcard Set

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Exam 1
N/A
37
Veterinary Medicine
Professional
02/20/2012

Additional Veterinary Medicine Flashcards

 


 

Cards

Term
T/F: The dog and cat have a completely bony orbit.
Definition
False: the horse has a completely bony orbit, while the dog and cat have an open orbit, which makes them a little more prone to damage of the face that can harm structures of the eye.
Term
The orbital lacrimal gland produces ____-____% of the aqueous tears, while the third eyelid gland produces ____-____% of the aqueous tears.
Definition
60-70% from orbital lacrimal gland
30-40% from third eyelid gland
Term
Drainage of aqueous tears goes from the ________________ to the ________________ to the ________________ and exits from the ____________________.
Definition
Lacrimal puncta
Canaliculi
Nasolacrimal duct
Nasal punctum
Term
The oculomotor nerve is responsible for innervation of all of the following muscles except:

a. Superior rectus m.
b. Inferior oblique m.
c. Lateral rectus m.
d. Inferior rectus m.
e. Medial rectus m.
Definition
c. Lateral rectus m.

Innervated by CN6 (Abducens n.)
Term
The superior oblique muscle of the eye is innervated by:

a. CNIII
b. CNIV
c. CNVI
d. CNVII
e. None of the above
Definition
b. CNIV
Term
The abducent nerve is responsible for innervation of the:

a. Lateral Rectus Muscle
b. Retractor Bulbi Muscle
c. Medial Rectus Muscle
d. A and B
e. B and C
Definition
d. A and B
Term
T/F: the eyelids have a muscle called Muller's muscle, which has sympathetic innervation and is the reason why animals with Horner's syndrome have ptosis.
Definition
True
Term
T/F: the third eyelid is made up of cartilage and a lacrimal gland.
Definition
True--the lacrimal gland is responsible for 30-40% of aqueous tear production, which is why it is important to try and preserve the third eyelid gland when doing surgery/treatment.
Term
List four types of conjunctiva (based on location) found in the eye:
Definition
Bulbar
Palpebral
Nicitans
Fornices
Term
The vascular tunic is made up of the __________, ___________, and _____________.
Definition
Iris
Ciliary Body
Choroid
Term
All of the following are layers of the cornea except:

a. Epithelium
b. Stroma
c. Descemet's membrane
d. Endothelium
e. Sclera
Definition
e. Sclera
Term
In the cornea, the ____________ and _____________ are lipophilic, while the ________________ is hydrophilic. The ______________ is the thickest layer of the cornea.
Definition
Epithelium, Descemet's membrane are lipophilic
Stroma is hydrophilic
Stroma is thickest
Term
The ______________ removes fluid from the cornea to maintain relative dehydration/clarity.

a. Epithelium
b. Stroma
c. Descemet's membrane
d. Endothelium
e. None of the above
Definition
d. Endothelium
Term
T/F: the stroma in the cornea is made up of irregularly arranged collagen fibers, while the sclera is made up of regularly arranged collagen fibers.
Definition
False

Stroma = regularly arranged collagen
Sclera = irregularly arranged collagen
Term
The ________________ is the area of transition from cornea to sclera.
Definition
Limbus
Term
The ________________ is the area of transition from cornea to sclera.
Definition
Limbus
Term
The weakest point of the eye is the:

a. Limbus
b. Lamina cribrosa
c. Retina
d. Iris
e. Lens
Definition
b. Lamina cribrosa
Term
The uvea is made up of the _____________, _____________, and _____________.
Definition
Iris
Ciliary body
Choroid
Term
T/F: pupillary membranes are clinically significant in the dog.
Definition
False: residual change when embryonic vasculature is not broken down completely
Term
The pupillary ruff:

a. Refers to a pupillary difference in large animal species
b. Is sometimes referred to as the corpora nigrans
c. Is sometimes referred to as the granula iridica
d. A and B
e. A, B, and C
Definition
e. A, B, and C
Term
Innervation to the pupillary sphincter muscle is through:

a. CNII
b. CNIII
c. CNIV
d. CNVI
Definition
b. CNIII
Term
T/F: the pupillary sphincter muscle is stronger than the pupillary dilator muscle, so when the eye is inflamed, miosis will occur.
Definition
True
Term
T/F: innervation to the pupillary dilator muscle is parasympathetically mediated.
Definition
False. Sympathetically mediated.
Term
The ciliary body:

a. has zonular attachments that go 360 degrees around the lens to hold the lens in place
b. produces aqueous humor through its non-pigmented epithelial cells
c. Has zonules that contract for near vision
d. Has zonules that relax for far vision
e. All of the above
Definition
e. All of the above
Term
T/F: the majority of aqueous humor drains out the iridocorneal angle.
Definition
True. There is a second pathway that allows absorption by the stroma, which can be medically mediated for glaucoma treatment.
Term
The normal intraocular pressure for horses is:

a. 5-10 mmHg
b. 10-20 mmHg
c. 20-30 mmHg
d. 30-40 mmHg
e. 40-50 mmHg
Definition
c. 20-30 mmHg

Dogs/cats are 10-20 mmHg
Term
Lens fibers:

a. Are regularly exposed to the rest of the eye
b. Undergo aging degeneration called nuclear sclerosis that is the equivalent to cataracts.
c. Will stimulate inflammation in the eye if the lens fibers are recognized as foreign antigen
d. A and B
e. A, B, and C
Definition
c. will stimulate inflammation

The lens fibers are never exposed to the eye--if the lens is damaged, this will stimulate inflammation in the eye because it is a foreign antigen in the eye. Nuclear sclerosis is an aging process, but is NOT equivalent to cataracts.
Term
The _______________ maintains eye shape and retinal position, transmits light, and is 99% water.

a. Aqueous humor
b. Uvea
c. Vitreous body
d. Retina
e. Cornea
Definition
c. Vitreous

The retina is only connected at the aura and at the optic nerve, so vitreous helps maintain retinal position
Term
The fundus is made up of:

a. Retina
b. Choroid
c. Tapetum
d. Sclera
e. All of the above
Definition
e. all of the above

The tapetum is a structure that gives the retina a second chance at processing light
Term
The workhorses of the retina are the __________________.
Definition
Photoreceptors

Rods--dim light, peripheral vision
Cones--daylight, color, visual acquity
Term
If an animal has an anangiotic vascular pattern in the retina, where does the vascular supply come from?
Definition
The choroid

Various vascular patterns: Merangiotic, anangiotic, paurangiotic, holangiotic
Term
The choroid:

a. Contains the stars of Winselow
b. Is typically pigmented
c. Sometimes contains the tapetum, which reflects unabsorbed light rays back to photoreceptors.
d. A and B
e. A, B, and C
Definition
e. A, B, and C

Note that the stars of Winselow are another name for the choriocapillaries, which are responsible for being the main nutrition source for the outer retina
Term
_____________ do not have much myelin around their optic nerve, making it appear black, rather than white.
Definition
Cats
Term
The _______________ gives photoreceptors a second chance at light.
Definition
Tapetum
Term
Describe the visual pathway:
Definition
Optic nerve-->optic chiasm-->decussation (50-100% depending on species)-->optic tract where 80% of fibers go to the lateral geniculate nucleus of the thalamus-->optic radiations-->cerebral cortex (occipital lobe)-->visual processing
Term
Describe the PLR pathway:
Definition
Optic nerve-->optic chiasm-->species specific decussation-->optic tract to pretectal nuclei (20% of fibers)-->decussation-->parasympathetic nuclei of CNIII -->parasympathetic fibers of CNIII synapse in ciliary ganglion-->short posterior ciliary nerves terminate at iris sphincter
Term
T/F: a blind dog can have a normal PLR
Definition
True

Any impediment to ocular clarity can provide a normal PLR but cause the dog to be functionally blind. Similarly, dogs with brain disease where the optic centers aren't functioninc properly may have an optic nerve that is functioning just fine.
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