Middle Tunic (Uveal tract)

Question 1

Middle Tunic (Uveal tract)

Answer 1

• Main function is to provide nutrition to the globe

- Consists of the iris, ciliary body and choroid

Question 2

Iris

Answer 2

Outgrowth of the ciliary body. It contains 2 muscles to control the amount of light that enters the eye.

• The dilator pupillae muscle
• The sphincter pupillae muscle

Question 3

Dilator pupillae muscle

Answer 3

Makes the pupil larger

Question 4

Sphincter pupillae muscle

Answer 4

Constricts the pupil

Question 5

Pupils

Answer 5

The opening of the eye. Pupils should be equal, round and regular.

Question 6

Miosis (Pupil constriction)

Answer 6

Occurs during sleep, when the eyes converge, during bright light situations, or when
using miotic drugs

Question 7

Mydriasis (pupil dilation)

Answer 7

Occurs in low light situations or

when a person is in a state of excitement

Question 8

Ciliary Body

Answer 8

Consists of the ciliary muscle and the ciliary processes

Question 9

Ciliary muscle

Answer 9

Works with the crystalline lens during accommodation

Question 10

Ciliary processes

Answer 10

Secretes aqueous humor into the eye

Question 11

Choroid

Answer 11

Highly pigmented layer that extends from the optic nerve to the ciliary body. A very dark brown layer, it consists of numerous arteries and vessels that supply the iris, ciliary body, sclera and choroid itself, with nutrients.

-Only the choroid blood vessels that extend to the episclera and limbus are visible
when examining the eye.

(Ref. notes in study guide on how to determine where an eye problem is occuring.)