Eye muscles - Intrinsic

Question 1

List 2 functions of the intrinsic eye muscles?

Answer 1

1. Control pupil diameter

2. Changes curvature of lens

Question 2

List the 3 intrinsic eye muscles.

Answer 2

1. Ciliary muscle
2. Constrictor pupillae
3. Dilator pupillae

Question 3

Where is the ciliary muscle found?

Answer 3

In the ciliary body.

Question 4

Where is the constrictor pupillae found?

Answer 4

In the iris at the pupillary border.

Question 5

What is the orientation of the dilator pupillae and where are they found?

Answer 5

1. Radial

2. In the iris

Question 6

How is the the ciliary muscle innervated?

Answer 6

Parasympathetic branch of oculomotor (III)

Question 7

How is the the constrictor pupillae innervated?

Answer 7

Parasympathetic branch of oculomotor (III)

Question 8

How is the the dilator pupillae innervated?

Answer 8

1. Dilation controlled by sympathetic branch of oculomotor (III)
2. Constriction controlled by parasympathetic branch of Oculomotor (III)

Question 9

What is the pupillary reaction to increased illumination or close objects?

Answer 9

1. Parasympathetic branch of oculomotor (III) causes the sphincter pupillae to contract
2. Pupil constricts to prevent light entering.

Question 10

What is the pupillary reaction to decreased illumination or distant objects?

Answer 10

1. Sympathetic branch of oculomotor (III) causes the dilator pupillae muscle to contract
2. Pupil dilates allowing more light to enter.