The Orbit

Question 1

What bones are involved in the orbit

Answer 1

Frontal, zygomatic, maxilla, ethmoid, sphenoid and lacrimal

Question 2

What is within the orbit

Answer 2

Eyeball, fat and connective tissue, extraocular muscles, nerves and blood vessels

Question 3

What are the tarsal plates composed of

Answer 3

Dense connective tissue

Question 4

What is the function of the tarsal plates

Answer 4

Support the eyelid and contain glands that secrete a watery fluid to lubricate the eyeball

Question 5

What are the ligaments of the eye

Answer 5

Cheek and suspensory ligaments

Question 6

Function of the suspensory ligament

Answer 6

Support the eyeball

Question 7

Function of the cheek ligament

Answer 7

Restrict the movements of the medial and lateral recti

Question 8

What is the eyeball composed of

Answer 8

Cornea, sclera, iris, ciliary body, choroid and retina

Question 9

What makes up the fibrous outer coat of the eyeball

Answer 9

The cornea and sclera

Question 10

What makes up the middle layer of the eyeball

Answer 10

The vascular layers

Question 11

What is the retina composed of

Answer 11

Rods and cones

Question 12

What does the retina make up

Answer 12

The inner coat

Question 13

What is the blind spot within the retina

Answer 13

The optic disc

Question 14

What is the macula lutea

Answer 14

The fovea of the retina

Question 15

What makes the aqueous humor

Answer 15

Ciliary body

Question 16

What is the function of the aqueous humor

Answer 16

Helps to maintain intra-ocular pressure

Question 17

Where is aqueous humor drained into

Answer 17

The corneo-scleral junction by the canal of Schlemm

Question 18

What is the vitreous humor

Answer 18

Embryological, transparent jelly, posterior to the lens that supports the retina

Question 19

What is the function of the dilator pupilae muscles

Answer 19

Increases the diameter of the pupil

Question 20

What innervates the dilator pupillae muscles

Answer 20

Sympathetic fibres

Question 21

What does the sphincter pupilae muscle do

Answer 21

Decrease the diameter of the pupil

Question 22

Innervation of the sphincter pupillae muscles

Answer 22

Parasympathetic fibres via the oculomotor nerve

Question 23

What are int intrinsic eye muscles

Answer 23

Ciliary muscle

Question 24

Function of the intrinsic muscles of the eye

Answer 24

Change the shape of the lens for accommodation

Question 25

What innervates the intrinsic eye muscles

Answer 25

The oculomotor nerve

Question 26

What are the 7 extraocular muscles

Answer 26

Levator palpabrae superioris, superior oblique, inferior oblique and the superior, inferior, medial and lateral recti

Question 27

Where does the levator palpabrae superioris run from/to

Answer 27

The orbital roof to the upper eyelid

Question 28

Where do the superior, inferior, medial and lateral recti run from/to

Answer 28

The annular ring to to the sclera, anterior to the equator

Question 29

Where does the superior oblique run from/to

Answer 29

The lesser sphenoid wing to the sclera, posterior to the equator

Question 30

Where does the inferior oblique run from/to

Answer 30

The orbital floor to the sclera, posterior to the equator

Question 31

Why are the axes of orbit and optical axis different

Answer 31

So the eye muscles can move in more than one direction

Question 32

What does the lacrimal apparatus produce

Answer 32

Tears

Question 33

What innervates the lacrimal apparatus

Answer 33

Secretomotor fibres from the facial nerve