Anatomy

Question 1

What 7 bones make up the orbit?

Answer 1

Frontal
Zygomatic
Sphenoid
Ethmoid
Lacrimal
Palatine

Question 2

What are the 5 bony feature of the orbit?

Answer 2

Orbital plates
Optic canal
Superior orbital fissure
Supraorbital notch/foramen (branch of CNV1)
Infraorbital foramen (branch CNV2)

Question 3

Which cranial nerves pass through the superior orbital fissure?

Answer 3

CNIII (oculomotor)
CNIV (trochlea)
CNV1 (trigeminal, ophthalamic)
CNVI (abducens)

Question 4

What muscle makes up the external part of the eyelid?

Answer 4

orbicularis oculi

Question 5

What are the two parts of the orbicularis oculi?

Answer 5

Orbital (tight closure)

Palpebral (gentle closure)

Question 6

What nerve controls the orbicularis oculi?

Answer 6

CNVII (facial)

Question 7

What 6 connective tissues make up the deeper part of the eyelid?

Answer 7

Tendon of levator palpebrae superioris
Superior tarsus
Inferior tarsus
Medial palpebral ligament
Lateral palpebral ligament
Orbital septum

Question 8

What is the function of the levator palpebrae superioris?

Answer 8

Elevates the upper eyelid

Question 9

What muscle (adjoined to the levator palpebrae superioris) allows for extra widening of the eye?

Answer 9

Superior tarsus muscle (Mueller’s muscle)

Question 10

What gland is responsible for lipid secretion that lines the eyelids?

Answer 10

Tarsal glands/Meibomian glands

Question 11

Where is the lacrimal gland located?

Answer 11

Superior-laterally to the orbit

Question 12

What nerve supplies parasympathetic secretomotor innervation to the lacrimal gland?

Answer 12

CNVII (facial)

Question 13

Name the 7 extraocular muscles?

Answer 13

Superior rectus
Inferior rectus
Medial rectus
Lateral rectus
Superior oblique
Inferior oblique
Levator palpebrae superioris

Question 14

What is the trochlear?

Answer 14

A loop of connective tissue

Question 15

What is the innervation of superior rectus?

Answer 15

CNIII (oculomotor)

Question 16

What is the innervation of inferior rectus?

Answer 16

CNIII (oculomotor)

Question 17

What is the innervation of medial rectus?

Answer 17

CNIII (oculomotor)

Question 18

What is the innervation of lateral rectus?

Answer 18

CNVI (abducens)

Question 19

What is the innervation of superior oblique?

Answer 19

CNIV (trochlear)

Question 20

What is the innervation of levator palpebrae superioris?

Answer 20

CNIII (oculomotor)

Question 21

What is the origin of and insertion of the 4 rectus muscles?

Answer 21

Origin: common tendinous ring
Insertion: sclera

Question 22

What is the origin and insertion of the superior oblique?

Answer 22

Origin: sphenoid bone
Insertion: sclera

Question 23

What is the origin and insertion of the inferior oblique?

Answer 23

Origin: orbital plate of maxilla
Insertion: sclera

Question 24

What is the origin and insertion of the levator palpebrae superioris?

Answer 24

Origin: lesser wing of sphenoid
Insertion: skin and tarus of superior eyelid

Question 25

What is the function of superior rectus?

Answer 25

Elevates, adducts and medially rotates the eyeball

Question 26

What is the function of inferior rectus?

Answer 26

Depresses, adducts and laterally rotates the eyeball

Question 27

What is the function of medial rectus?

Answer 27

Adducts eyeball

Question 28

What is the function of lateral rectus?

Answer 28

Abducts the eyeball

Question 29

What is the function of superior oblique?

Answer 29

Depresses, abducts and medially rotates eyeball

Question 30

What is the function of inferior oblique?

Answer 30

Elevates, abducts and laterally rotates eyeball

Question 31

How do you examine superior rectus?

Answer 31

Look laterally and up | when in abduction SR can only elevate

Question 32

How do you examine inferior rectus?

Answer 32

Look laterally and down | when in abduction IR can only depress

Question 33

How do you examine medial rectus?

Answer 33

Look medially

Question 34

How do you examine lateral rectus?

Answer 34

Look laterally

Question 35

How do you examine superior oblique?

Answer 35

Look medially and down | when in adduction can only depress

Question 36

How do you examine inferior oblique?

Answer 36

Look medially and up | when in adduction can only elevate

Question 37

What are the 3 layers of the eye?

Answer 37

Fibrous Uvea Retina

Question 38

What makes up the fibrous layer of the eye?

Answer 38

Sclera | Cornea

Question 39

What makes up the uvea?

Answer 39

Iris Ciliary body Choroid

Question 40

What are the functions of the ciliary body?

Answer 40

Controls iris Controls the shape of the lens Controls the secretion of aqueous humour

Question 41

What is a feature of the choroid?

Answer 41

Highly vascular

Question 42

What is a feature of the retina?

Answer 42

Photosensitive

Question 43

What is the anterior segment made up of?

Answer 43

Anterior chamber | Posterior chamber

Question 44

Where is the anterior segment located?

Answer 44

In front of the lens

Question 45

Where is the anterior chamber located?

Answer 45

Between the cornea and iris

Question 46

Where is the posterior chamber located?

Answer 46

Between the iris and the suspensory ligaments

Question 47

Where is the posterior segment and what does it contain?

Answer 47

Behind the lens | Vitreous humour

Question 48

What are the steps in aqueous humour circulation?

Answer 48

1. Ciliary body secretes AH into the posterior chamber 2. AH circulates within PC and nourishes the lens 3. AH passes through the pupil into the AC and nourishes the cornea 4. AH is reabsorbed/drained into the canal of Schlemm at the iridocorneal angle

Question 49

Balance between secretion and drainage of _____ is important in maintaining ____ pressure

Answer 49

Aqueous humour | Intraocular pressure