Anatomy of eye

Question 1

Tissues surrounding the eye as a whole including muscles, eyelids, TEL, lacrimal glands, fat, nerves, vessels etc…

Answer 1

Adnexa

Question 2

What are 4 rectus muscles of the eye and what is their innervation?

Answer 2

dorsal, ventral, and medial –> innervated by CN III oculomotor

lateral –> innervated by CN VI abducens

Question 3

What are the 2 oblique muscles, their innervation, and direction in which they move they globe of the eye?

Answer 3

Dorsal oblique –> innervated by CN IV (trochlear) –> rotates the dorsal globe medioventral

Ventral oblique –> innervated by CN III (oculomotor) –> rotates ventral globe mediodorsally

Question 4

What is the innervation to the retractor muscle?

Answer 4

CN VI (abducens) and a smooth muscle cone is innervated by sympathetic fibers

*not found in the bird!

Question 5

What are the 3 layers to the globe of the eyeball?

Answer 5

1. Outer fibrous = cornea and sclera
2. middle vascular = uvea - including iris, ciliary body, and choroid
3. Inner nervous = retina

*note - the tapetum lies in between the choroid and retina in species/coat colors that have them.

Question 6

What is the lens?

Answer 6

a transparent, refractile disk located behind the iris.

Question 7

How is the lens held in position?

Answer 7

by lens zonules which come off of the ciliary process

Question 8

What is the lens made of and how is it nourished?

Answer 8

Protein and water ( with no innervaiton or blood supply);

Nourished by the aqueous and vitreous humor!

Question 9

What produces the aqueous humor and where does it live in the eye?

Answer 9

Aqueous humor is produced by the ciliary processes behind the iris –> passes through the pupil and lives in the anterior chamber

Question 10

How does aqueous humor exit the eye?

Answer 10

at the iridocorneal angle where the iris and cornea meet

Question 11

_________ is the largest area of the eye.

Answer 11

Vitreous

Question 12

________ ________ is a clear gel like substance that lives between the lens and retina

Answer 12

Vitreous humor

Question 13

What is the function of the vitreous humor?

Answer 13

provides nutritional and structural support to the lens and the retina

Question 14

Where to the ganglia and axons of the retina come from?

Answer 14

They converge from the optic nerve

Question 15

What layers must be transparent to visualize the retina?

Answer 15

cornea, aqueous humor, lens, and vitreous

Question 16

What is the motor innervation of the levator muscle of the eyelids?

Answer 16

CN III (oculomotor)

Question 17

What is the motor innervation of the obicularis oculi muscle (which closes the eyelid)?

Answer 17

CN VII (facial)

Question 18

What is the sensory innervation to the eyelids?

Answer 18

CN V (trigeminal)