Anatomy of the eye (1)

Question 1

Where do the axons from the optic tract synapse?

Answer 1

Lateral geniculate nucleus

Question 2

What 5 bones of the skull make up the orbit?

Answer 2

1. Frontal
2. lacrimal
3. zygomatic
4. sphenoid
5. palatine

Question 3

What are the main differences between herbivorous and carnivorous orbits?

Answer 3

Carnivores (and pigs) have incomplete orbit; connected by orbital lig.

Question 4

What structures pass through the orbital foramina?

Answer 4

Ophthalmic artery and vein and orbital vein. Also many CNs

Question 5

What does the periorbital fascia contain?`

Answer 5

extra-ocular muscles, nerves, vessels

Question 6

What extra-ocular muscle do birds and reptile lack?

Answer 6

Retractor bulbi`

Question 7

Which muscles does III, occulomotor nerve innervate?

Answer 7

• D rectus
• V rectus
• M rectus
• V oblique

Question 8

Which 2 muscles is the Abducens nerev innervate?

Answer 8

• L rectus

- Retractor bulbi

Question 9

Name two/three layers of orbital fascia

Answer 9

1. Peri-orbital fascia

2. Fascia Bulbi

Question 10

What are meibomian glands?

Answer 10

• produce lipid layer

* open onto margin

Question 11

Canthal ligaments are also called?

Answer 11

Palpebral lig

Question 12

Which canthal ig is missing in dogs?

Answer 12

Lateral

Question 13

What is Distchiae?

Answer 13

When hairs grow out of the Meibomian glands and damage cornea

Question 14

What is the function of Orbicularis Oculi and what innervates it?

Answer 14

• closes eyelids

- Facial

Question 15

Levator Palpebrae Superioris is innervated by..

Answer 15

Occulomotor

Question 16

Both lat and med retractor anguli oculi are innervated by..

Answer 16

Facial

Question 17

What nerve is responsible for the sensory aspect of the eyelids?

Answer 17

Trigem, ophthalmic and maxillary branches

Question 18

What is the Lacrimal Caruncle and what animal?

Answer 18

Horses,

Exposed pigmented sclera

Question 19

What are three components of tears and what glands produce them?

Answer 19

1. Lipid; Meibomian glands on 3rd eyelid
2. Mucin : Goblet cells on conjunctiva at Bulbal surface
3. Aqueous: 3rd eyelid gland and lacrimal glands.

Question 20

What epithelium is the anterior epithelium of the cornea?

Answer 20

Stratified squamous superficially, becoming Columnar epi

Question 21

Describe the stroma of the eye

Answer 21

• Aligned collagen fibrils into lamellae
• keratinocytes
• ground substance

Question 22

What is the Descemets membrane

Answer 22

underlying endothelial membrane in posterior cornea

Question 23

What does the Descemets membrane do?

Answer 23

ensure dehydration of the cornea to remain clear