Eye Development (Kiem)

Question 1

Describe the developmet of the optic cup

Answer 1

An extension of the prosencephalon that grows outward (optic vesicle). The long part of the extension is the optic stalk. The inferior part of the optic vesicle and optic stalk has an optic fissure which will close.

Question 2

Aniridia

Answer 2

Lack of iris tissue or complete absence of the iris.

It is a problem with the rim of the optic cup to develop.

Question 3

What does the rim of the optic cup give rise to?

Answer 3

Iris and ciliary body.

Question 4

What are the inner and outer layers of the retina?

Answer 4

Inner is neural retina.

Outer is pigmented retina.

Question 5

What induces the lens placode?

Answer 5

The optic cup touching the surface ectoderm.

Question 6

What types of epithelium is the anterior lens epithelium?
Primary lens epithelium?
Secondary lens epithelium?

Answer 6

Ant - cuboidal
Primary - columnar
Secondary - cuboidal

Question 7

Congenital cataracts

Answer 7

Lens is opaque/grayish white.
Can be caused by Rubella infection radiation, enzyme deficiency (congenital galactosemia).

Problem of lens only.

Question 8

Aqueous humor is absorbed by? Secreted by?

Answer 8

Absorbed by scleral venous sinus in anterior chamber, and secreted by ciliary epithelium in posterior chamber.

Question 9

Where is vitreous humor from?

Answer 9

Choroid

Question 10

Where is aqueous humor from?

Answer 10

Ciliary process

Question 11

What causes congenital glaucoma?

Answer 11

Increased introcular pressure from abnormal drainage of aqueous humor.

Question 12

What makes extra-ocular muscles?

Answer 12

Prechordal mesenchyme

Question 13

What will become central retinal a.?

Answer 13

Hyaloid a.

Supplies embryological eye.

Question 14

Persistence of hyaloid a.

Answer 14

Distal hyaloid a. persists. Small squiggly worm-like structure in eye. Eyes can be microphthalmic.

Question 15

What becomes the optic n.?

Answer 15

Axons from retinal ganglion cells. The optic stalk is only the template.

Question 16

Papilledema

Answer 16

Increased intracranial pressure slows venous return from retina, causing accumulation of fluid in optic disk.
Edema occurs because the retinal vessels are covered by meninges and lie in the extension of the subarachnoid space.

Question 17

Coloboma

Answer 17

Results in abnormal closure of optic fissure.

Question 18

What does neuroectoderm become? (4)

Answer 18

Pigmented layer of retina
Neural layer of retina
Ciliary body (rim of optic cup)
Iris (rim of optic cup)

Question 19

What does surface ectoderm become? (2)

Answer 19

Lens

Epithelium of cornea

Question 20

What does NCCs become? (5)

Answer 20

Sclera
Stroma of cornea
Choroid
Stroma of iris
***Ciliary muscles***