Ophthalmic Anatomy - Adnexa: Orbit, Orbital Fascia, Extraocular Muscles And Fat, And The Orbit

Front 1

Carnivores possess enhanced _____________ vision to improve predatory feeding habits

Back 1

binocular

Front 2

What type of vision yields a larger area of panoramic vision for ungulates?

Back 2

monocular

Front 3

where in the orbit is the dog's eye located with regards to midline?

Back 3

rostrolateral, 10 degrees from midline

Front 4

What species have an entirely enclosed orbit?

Back 4

horse, ox, sheep, cattle, goat

Front 5

what species have an open orbit?

Back 5

carnivore, pig

Front 6

What is the bone structure of the dog/cat orbit?

Back 6

5, sometimes 6 bones
frontal
zygomatic
lacrimal
sphenoid
palatine
+/- maxillary

Front 7

what are the 3 entities that comprise the orbital fascia?

Back 7

periorbita, Tenon's capsule (fascia bulbi), fascial sheaths of the extraocular muscles

Front 8

What represents the yellow color in periorbital fat of animals?

Back 8

lutein, beta caroten, and retinol

Front 9

What is the insertion of the 4 rectus muscles (be specific)?

Back 9

Medial - 5 mm away from the limbus
Ventral - 6 mm away from the limbus
Dorsal - 7 mm away from the limbus
Lateral - 9 mm away from the limbus

Front 10

In which direction does the dorsal oblique muscle pull the globe?

Back 10

medially, ventrally

Front 11

In which direction does the ventral oblique pull the globe?

Back 11

medially, dorsally

Front 12

What extraocular muscles are innervated by the oculomotor nerve (CN III)?

Back 12

dorsal, ventral, and medial recti, ventral oblique

Front 13

What extraocular muscles are innervated by the abducens nerve (CN VI)?

Back 13

lateral rectus, retractor oculi

Front 14

What extraocular muscles are innervated by the trochlear nerve (CN IV)?

Back 14

dorsal oblique

Front 15

Where does the medial palpebral ligament insert?

Back 15

the periosteum of the nasal bone

Front 16

Where does the lateral palpebral ligament insert?

Back 16

temporal fascia and bones associated with the lateral orbit

Front 17

what muscle(s) are responsible for closure of the eyelids?

Back 17

orbicularis ocululi

Front 18

what muscle(s) are responsible for open of the eyelids?

Back 18

relaxation of the orbicularis oculi and contraction of the levator palpebrae superioris

Front 19

How many rows of eyelashes do dogs have?

Back 19

2-4

Front 20

do cats have upper eyelashes?

Back 20

technically no; however the first row of hairs are close enough that some consider them eyelashes

also seen in the elephant and hyrax

Front 21

What is the function of the eyelid (3)?

Back 21

1. protection/exclusion from light
2. production of a portion of liquid tears
3. spreading of the precorneal tear film/sweeping away of foreign material

Front 22

What are the 4 histologic layers of the eyelid?

Back 22

1. skin
2. orbicularis oculi
3. tarsus and stromal layer
4. palpebral conjunctival layer

Front 23

glands of Zeis

Back 23

sebaceous glands of the eyelid

Front 24

glands of Moll

Back 24

aka ciliary glands; modified sweat glands of the eyelid

Front 25

glands of Kraus

Back 25

found in the human; accessory sweat glands of the conjunctiva

Front 26

meibomian glands

Back 26

tarsal glands that contribute to the outer oily layer of the preocular tear film

Front 27

what large terrestrial animal lacks meibomian glands?

Back 27

elephant

Front 28

what are the mucus forming cells found in the conjunctiva?

Back 28

goblet cells

Front 29

where is the highest concentration of goblet cells in the dog?

Back 29

lower nasal and middle fornix and lower tarsal portion of the palpebral conjunctiva

Front 30

what is the blood supply of the conjunctiva?

Back 30

branches of the anterior ciliary arteries (branches of the external ophthalmic artery

Front 31

What cells dominate the diffuse portion of the CALT?

Back 31

CD-8 positive suppressor cells, cytotoxic effector cells

Front 32

What cells dominate the follicular portion of the CALT?

Back 32

lymphocyte activation, proliferation and effector cell differentiation

Front 33

What is the lymphatic drainage of the lateral commissure of the conjunctiva?

Back 33

parotid lymph nodes

Front 34

What is the lymphatic drainage of the medial conjunctiva?

Back 34

sumaxillary lymph nodes

Front 35

what are the main functions of the conjunctiva (3)?

Back 35

1. prevent dessication of the cornea
2. increase mobility of the eyelid and globe
3. provide a physiologic barrier against microrganisms and foreign bodies

Front 36

what is the nictitans cartilage primary made of in the horse? dog?

Back 36

largely elastic in the horse; hyaline in the dog

Front 37

name the function (mixed, serous, mucus) of the nictitans gland in the horse, dog, cat, cow, and pig:

Back 37

horse - serous
dog/cat/cow - mixed
pig - mucus

Front 38

Harderian gland

Back 38

accessory lacrimal gland; found primarily in the rodent

Front 39

what domestic species has smooth muscle associated with the third eyelid?

Back 39

cat

Front 40

what is the name of the skeletal muscle in the manatee that is associated with the third eyelid? what is it's innervation?

Back 40

pyrimidalis muscle; innervated by the oculomotor nerve

Front 41

what are the 3 layers of the preocular tear film?

Back 41

1. oil
2. aqueous
3. mucus

Front 42

what glands produce the oil layer of the preocular tear film?

Back 42

meibomian glands, glands of Zeis

Front 43

What percentage of the aqueous layer of the tear film is produced by the lacrimal gland, accessory gland of Kraus and Wolfring, and the gland of the third eyelid respectively?

Back 43

lacrimal - 61%
accessory glands - 3%
gland of the third eyelid- 35%

Front 44

where is the mucin layer of the preocular tear film produced?

Back 44

largely by conjunctival goblet cells

Front 45

what effect do cholinergic drugs have on the lacrimal gland?

Back 45

stimulation

Front 46

What type of drug will decrease tear production?

Back 46

anticholinergics (ie atropine!)