Lecture 15 and 16

Question 1

What is the name of the bony hollow that the eye sits in?

Answer 1

The orbit

Question 2

What is the name of the structure that completes the bony orbit within cats and dogs?

Answer 2

The orbital ligament

Question 3

What is meant by the term periorbita?

Answer 3

Refers to the fibrous cone of the orbit, has periorbital fat on the inside and on the outside. The origin of the cone is down near the formina.

Question 4

If something is described as being palpebral what is it most likely to be associated with?

Answer 4

The eyelid

Question 5

Th gap between the two eyelids is called a _________

Answer 5

palpebral fissure

Question 6

What is the corner of the eyelid called?

Answer 6

angles

Question 7

The __ (1- 2 words)_____ is a small mound at the medial angle. The function is to form a ___(2- 2 words)_______

Answer 7

1) Lacrimal caruncle 2) Lacrimal lake

Question 8

What is the correct anatomical term for the eyelashes?

Answer 8

cilia

Question 9

You are a surgeon cutting through the eyelid describe the layers you would encounter as you are cutting through.

Answer 9

1) First layer cutting through is epithelium 2) Obicularis oculi layer (+ levator of the upper eyelid) 3) Tarsus (stiff fibrous rod) 4) Tarsal glands (opening along the eyelid)

Question 10

What is the name of the structure that the eyelids open into?

Answer 10

Conjunctival sac

Question 11

What is meant by the term fornix?

Answer 11

Point at which the conjunctiva transforms from palpebral conjunctiva to bulbar conjunctiva is referred to as the fornix

Question 12

What is the main function of the tarsal glands within the eyelid?

Answer 12

Secrete a sebaceous fluid that effectively waterproofs the eyelid

Question 13

What is another (better?) name for the third eyelid?

Answer 13

nictitating membrane

Question 14

The shape of the membrane in the third eyelid is in the shape of what letter?

Answer 14

T

Question 15

What is the name of the condition resulting from an inflamed Nictitans gland?

Answer 15

Cherry eye

Question 16

The nictitans gland produces about 40% of tear secretion, where does the other 60% come from?

Answer 16

Lacrimal glands

Question 17

Tear secretions generally consist of three different components, what are the three components that “tears” consist of and what gland(s) do they come from?

Answer 17

1. Superficial oily layer (tarsal glands) 2. Aqueous layer (tear glands) 3. Deep mucous layer (conjunctival goblet cells)

Question 18

The ventral, dorsal and medial rectus muscles are innervated by cranial nerve III (oculomotor) nerve. However the lateral rectus is innervated by nerve ______(name and number)

Answer 18

VI (abducens nerve)

Question 19

What nerve innervates the dorsal oblique muscle?

Answer 19

IV (trochlear)

Question 20

Name the three layers of tunic from the outside to the inside

Answer 20

1) Fibrous 2) Vascular 3) Nervous

Question 21

Name the structures of the fibrous tunic:

Answer 21

Sclera and the cornea meeting at the limbus

Question 22

What are the structures that compose the vascular tunic?

Answer 22

Choroid, ciliary body and the iris

Question 23

What structures comprise the nervous tunic?

Answer 23

Refers to the retina

Question 24

Name this structure:

Answer 24

Sclera

Question 25

What is the name of the structure where the angle changes between the sclera and the cornea?

Answer 25

Limbus

Question 26

What is the path of tear secretions from the eye?

Answer 26

1) Produced by the lacrimal duct and by the nictitians glands
2) Exits the eye through upper and lower lacrimal puncta
3) Goes to the lacrimal caliculus
4) Lacrimal sac
5) Nasolacrimal duct

Question 27

Where is the vitrous compartement of the eye located?

Answer 27

Behind the lens

Question 28

Where is the anterior chamber of the eye located?

Answer 28

Infront of the pupil

Question 29

Where is the posterior component of the eye located?

Answer 29

Located just behind the iris

Question 30

Describe the path of the aquous humour:

Answer 30

1) Produced in the ciliary body of the posterior chamber
2) Travels around the iris
3) Re-absorbed by the iro-corneal angle of the anterior compartement

Question 31

What is the function of the ciliary body and the ciliary processes?

Answer 31

They pull on the lens to change its shape referred to as lens accomodation

Question 32

Describe the structure of the lens of the eye:

Answer 32

The lens is constructed like an onion around a triangle. The traingular structure in the middle is referred to as the radii lentis.

Question 33

What is the ocular fundus?

Answer 33

The back of the eye

Question 34

Name each of the following structures shown below:

Answer 34

1. Ocular fundus
2. tapedum
3. non-tapedum
4. optic disk
5. Macula

Question 35

Describe the structure of the cornea:

Answer 35

The outermost layer consists of anterior epithelium, then anterior limiting membrane then substantia propria, then posterior limiting membrane, then posterior epithelium. The cornea is avascular but highly innervated by the ciliary nerve

Question 36

What is the name for the iridic granules that are observed withtin the eyes of horses?

Answer 36

corpora niagra

Question 37

Describe the structure of the retina:

Answer 37

Has a basement pigment epithelium and then a basement layer of rods and cones and then above this it is richly vascular and has large amounts of nervous tissue.

Question 38

What is meant by the term lamina cribrosa?

Answer 38

Mesh-like structure that the optic nerve passes through