Senses (I) EYES

Question 1

A patient has a defect in the formation of their ciliary muscles, what function of the eye will be most directly affected by this defect?

Answer 1

the movement of the lens

Question 2

What forms the white of the eye and protects and shapes the eye.?

Answer 2

Sclera

Question 3

What part of the eye is supplied with blood? Give its characteristics

Answer 3

The choroid
prevents light scatter
and absorbs light
anteriorly forms: a ciliary body which is a smooth muscle that encircles the lens and the Iris which regulates the amount of light that enters the pupil by changing its size. Its also a smooth muscle.

Question 4

What protein is found the lens that is transparent?

Answer 4

Crystalline

Question 5

Distinguish between rods and cones.

Answer 5

Rods
- has retinal (light absorbing taken from Vit A bound to an opsin membrane
- do not distinguish from colors
- allow us to see at night but only in black and white
- it is more sensitive to light

Cones (photopsin)
- has retinal but have 3 distinct opsins; green, blue, red,

Question 6

What has a mucous membrane and prevents drying?

Answer 6

Conjunctiva

Question 7

The iris regulates the amount of light the enters the pupil by changing its size. Explain how the pupil size changes due to the amount of light the enters.

Answer 7

When the pupil is dilated this indicates a low amount of light (sympathetic NS)
When there is lots of light enter the pupil, this results in the pupil getting smaller ( Parasympathetic NS)

Question 8

What type of epithelial tissue is found in the cornea?

Answer 8

Outside the cornea ( stratified squamous - Keratinzied)
inside ( simple columnar)

Question 9

If a patient has cone dystrophy (degeneration of cones), which disorder would you think they have?

Answer 9

colorblindness

Question 10

Light is refracted as it passes through the eye before being focused on the retina. Which is the pathway of light through the eye?

Answer 10

Cornea, AH, Pupil, lens, VH