anatomy of the eye and orbit

Question 1

What is the function of the cornea

Answer 1

The anterior 1/6 of the fibrous coat of the eye - Transparent and is a window to allow light rays to enter the eye balls - the collagen fibres are all the sam diameter and distance apart which allows light to enter without becoming scattered

Question 2

What is the function of the sclera

Answer 2

The opaque posterior 5/6 of the fibrous coat which gives attachment to the muscles of the eye

Question 3

What is the function of the cilliary body

Answer 3

Suspends the lens and produces aqueous humor

Question 5

What is the function of the iris

Answer 5

The colourful part of the eye - controls the diameter of the pupil and therefore how much light enters the eye

Question 6

What is the function of the retina

Answer 6

Has light sensitive rods and cones which lets us see

Question 8

What is the function of the choroid

Answer 8

Supplies blood to outer layers of the retina

Question 9

What is the lens

Answer 9

Transparent crystalline biconvex structure which is suspended by zonules which are suspensory ligaments which come from the cilliary body

Question 11

What is the anterior segment of the eye and what does it contain

Answer 11

Infront of the lens - aqueous humor

Question 12

What is the posterior segment of the eye and what does it contain

Answer 12

Posterior to the lens - contains vitreous humor

Question 13

What is the function of the aqueous humor

Answer 13

Maintains the intraocular pressure

Question 14

What is the function of the vitreous humor

Answer 14

helps cusion the retina

Question 15

Which nerve innervates to help close the eyelids

Answer 15

Facial nerve (CN VII)

Question 16

Which nerve helps elevate the eyelids

Answer 16

(CN III) - occulomotor nerve - controls LPS

Question 17

What is the conjuctiva

Answer 17

Thin vascular membrane that covers the inner surface of the eye lids but not the sclera

Question 18

Describe the lacrimal apparatus and crying

Answer 18

The lacrimal gland is situated in the orbit laterally. Parasympathetic from Facial nerve. Its ducts open into the conjunctival sac
During each blink, eyelids spread tears evenly on the surface of cornea
Tears drain through punctae on the medial side of each eyelid
Drains into lacrimal sac which sits over the lacrimal bone
Then drains through nasolacrimal duct into the inferior meatus of the nasal cavity.

Question 19

What muscles constrict the pupil and what innervates it

Answer 19

Constrictor pupillae - innervated by CN III - occulomotor

Question 20

What muscle dilates the pupil

Answer 20

Dilator pupillae

Question 21

What is the innervation of the extrinsic ocular muscles

Answer 21

SO4 LR6 everything else is 3

Superior oblique - trochlear nerve CN IV

Lateral rectus - CN VI - abducens nerve

Question 22

What innervates the lacrimal gland

Answer 22

Opthalmic division of trigeminal nerve (CNV1)

Question 23

Describe the central retinal artery and what it supplies

Answer 23

Travels within the substance of the optic nerve and supplies inner layers of the retina

Question 24

What supplies the other parts of the retina which the central retinal artery doesn’t supply

Answer 24

Posterior cilliary artery