The Eye

Question 1

Which group of animals have binocular vision (with large blind spot at the back of their head)

Answer 1

Predators

Question 2

Which group of animals have a wide ranging vision (with blind spots right in front of their nose and right behind their ears)

Answer 2

Prey

Question 3

From external to internal what are the layers of the eye?

Answer 3

Fibrous tunic, Vascular tunic, Nervous tunic

Question 4

What are the two parts of the fibrous tunic (front and back of eye)?

Answer 4

Cornea (front of eye) and Sclera (back of eye)

Question 5

What is the junction between the Cornea and Sclera?

Answer 5

Corneoscleral junction (limbus)

Question 6

What are the three parts of the vascular tunic?

Answer 6

Iris (front most), ciliary, choroid (back part)

Question 7

What is the function of the ciliary body?

Answer 7

Suspends the lens, and helps with accommodation (making lens more concave or more flattened)

Question 8

What is the function of the iris?

Answer 8

Dilates and constricts the pupil to control the amount of light let in

Question 9

What are the three parts of the ciliary body?

Answer 9

Zonular fibres (connected to iris), Ciliary Process (connects fibres to muscle), and ciliary muscle (contracts to change the lens shape)

Question 10

Where are iridic granules found?

Answer 10

On the dorsal surface of the iris in horses and ungulates

Question 11

What is the reflective layer on the back of the eye called?

Answer 11

Tapetum Lucidum

Question 12

How is the tapetum lucidum different in carnivores and herbivores?

Answer 12

Made up of crystals in carnivores

Made up of collagen in herbivores

Question 13

What are the proportions of the two parts of the retina?

Answer 13

Light sensitive part = 2/3

Blind part = 1/3

Question 14

What is the function of the optic disc?

Answer 14

Where all of the nerves in the retina concentrate into the optic nerve and sends/receives fibres to/from the brain tract

Question 15

What are the two types of humor and their relative viscosities?

Answer 15

Aqueous humour (very liquid) 
Vitreous humour (very viscous)

Question 16

What is the passage of aqueous humour from production to exit?

Answer 16

(1) Secreted from the ciliary body into the posterior chamber
(2) Passes through the pupil into the anterior chamber
(3) Passes between the cornea and iris to drain into the veins of the eye

Question 17

What is the most important function of the aqueous humor?

Answer 17

Maintaining intraoccular pressure