Orbit and eye

Question 1

Answer 1

Question 2

What are the 3 formaina at the apex of the orbit?

Answer 2

The optic foramen, superior orbital fissure and inferior orbital fissure

Question 3

What passes through the optic formane?

Answer 3

Optic nerve

Opthalmic nerve

Question 4

What passes throguh the superior orbital fissure?

Answer 4

• Cranial Nerve VI (Abducens)*
• Cranial Nerve IV (Trochlear)*
• Cranial Nerve III (Oculomotor)*
• Ophthalmic* division of Cranial Nerve V (V1)
• Ophthalmic veins*

Question 5

What passes through the inferior orbital fissure?

Answer 5

Inferior Ophthalmic division of Cranial Nerve V (V1)

Question 6

What is the type of view that is shown?

Answer 6

Occipitomental veiw

Question 7

What paranasal air sinuses can you see in this radiograph.

Answer 7

• Frontal*
• Maxillary*
• Ethmoid*

Question 8

This makes the floor of the orbit weak.

Answer 8

Infraorbotal groove

Question 9

What are the main contents of the orbit?

Answer 9

• Eye*
• Extrinsic ocular muscles*
• Ligaments supporting the eye*
• Optic, Oculomotor, Trochlear & Abducens* nerves
• Branches of Ophthalmic artery*
• The lacrimal (tear) apparatus*
• Orbital fat*

Question 10

What are the components of the outer fibrous layer of the eye?

Answer 10

Cornea and sclera

It is a complete layer

Question 11

What are the components of the middle vascular layer?

Answer 11

Ciliary body

Iris

Choroid

Is incomplete anteriorly. Anterior aperture (in iris) is called pupil

Question 12

What are the components of the inner sensroy layer?

Answer 12

Retina

Is present posteriorly but anteriorly it stops short just in front of equator of the eye

Question 13

What does the crystalline lens divide into?

Answer 13

The eye into an anterior and a posterior segment.

Question 14

The watery fluid in the anterior segment

Answer 14

Aqueous humour

Question 15

The gel in the posterior segment?

Answer 15

Vitreous humour

Question 16

Answer 16

Question 17

What part of the eye produces (secretes) aqueous humour?

Answer 17

Ciliary body

Question 18

What are the intrinsic muscles of the eye?

Answer 18

Ciliaris

Sphincter pupillae

Dilator pupillae

Question 19

What is the location, action and innervation of the ciliaris?

Answer 19

Question 20

What is the location, action and innervation of the sphincter constrictor pupillae?

Answer 20

Question 21

What is the location, action and innervation of the dilator pupillae?

Answer 21

Question 22

What are eye movement produced by?

Answer 22

Extrinsic muscles of the eye

Question 23

Basic ee movements

Answer 23

Question 24

What is intort and extort?

Answer 24

These movements occur when the head is tilted- In order to keep the eyeballs focused on an object the eyes rotate in the opposite direction.

Question 25

What is it called when the top of the eye rotates towards the nose?

Answer 25

Intort

Question 26

What are the 6 muscles of the eye?

Answer 26

Four of these are straight course and two are oblique

Question 27

the elevator of the upper eyelid is also considered as an extrinsic eye muscle even though it has no action on the eyeball itself. What is this muscle called?

Answer 27

Levator palpebrae superioris

Question 28

What innervates the levator palpebrae superioris?

Answer 28

Oculomotor nerve

Question 29

Answer 29

Question 30

Answer 30

Question 31

What are the functions of the medial rectus?

Answer 31

Adduction

Question 32

What are the functions of the lateral rectus?

Answer 32

Abduction

Question 33

What are the functions of the superior rectus?

Answer 33

Elevation Adduction Intorsion

Question 34

What is the function of the inferior rectus?

Answer 34

Depression Adduction Extorsion

Question 35

What is the function of the superior oblique muscles?

Answer 35

Depression Intorion Abduction

Question 36

What is the function of the inferior oblqiue?

Answer 36

Elavtion Extorsion Abduction

Question 37

Which is the only muscle that does not arise from the posterior aspect of the orbit?

Answer 37

Inferior oblqiue- Comes from inferior orbital fissure

Question 38

*Name the ligaments that prevent over-adduction and over-abduction of the eye.*

Answer 38

*Suspensory Ligament of eyeball – Lockwood’s Ligament*

Question 39

What is the function of the suspensory ligament of the eye

Answer 39

Support the eye & prevent downward displacement of the eyeball

Question 40

*Name the branch of the internal carotid artery that supplies the orbit and the eye.*

Answer 40

*Ophthalmic Artery*

Question 41

Which foramina in the orbit do the ophthalmic veins pass through to enter into the cavernous venous sinus in the cranial cavity?

Answer 41

Superior Orbital Fissure

Question 42

In which part of the orbit does this structure lie, medial or lateral?

Answer 42

Lacrimal Gland is lateral – Lacrimal Sac etc. Medial

Question 43

From which cranial nerve does parasympathetic innervation to this structure arise?

Answer 43

Facial nerve

Question 44

Into which meatus of the nasal cavity does it drain (via the nasolacrimal duct)

Answer 44

Drains into the inferior nasal meatus