Lecture 23

Question 1

Which bone makes up the roof of the orbit?

Answer 1

Frontal bone

Question 2

Which bone makes up the medial wall of the orbit?

Answer 2

Ethmoid bone

Question 3

Which bone makes up the floor of the orbit?

Answer 3

Maxilla

Question 4

Which bones make up the lateral wall of the orbit?

Answer 4

• Zygomatic (Anteriorly)
• Greater wing of the Sphenoid (Posteriorly)

Question 5

What is the eye lid lined by internally?

Answer 5

Conjunctiva, which is reflected onto the eyeball

Question 6

What are Tarsal Plates and what are their functions?

Answer 6

Dense fibrous tissue bands which strengthens the eyelids

Question 7

What is the function of the Tarsal glands?

Answer 7

Produce a oily secretion on the watery tearfill to keep the cornea moist

Question 8

What is the function of the Medial palpebral ligament?

Answer 8

Connects the eyelids to the medial margin of orbit

Question 9

What is the function of the Lacrimal gland?

Answer 9

Drains by about 10-12 small ducts onto the conjunctiva

Question 9

Where is the Lacrimal gland?

Answer 9

Lies in a fossa in lateral part of the roof of orbit

Question 10

Where is the Lacrimal sac?

Answer 10

Lodged within the lacrimal groove

Question 11

What is the origin of the Levator palpebrae superioris muscle?

Answer 11

Roof of orbit close to apex

Question 12

What is the innervation of the Levator palpebrae superioris muscle?

Answer 12

Oculomotor nerve

Question 13

What is the action of the Levator palpebrae superioris muscle?

Answer 13

Elevates upper eyelid

Question 14

What is the attachment of the Superior rectus?

Answer 14

Common tendinous ring at the apex of the orbit

Question 15

What is the action of the Superior rectus?

Answer 15

Elevates the eyeball

Question 16

What is the action of the Inferior rectus?

Answer 16

Depresses the eyeball

Question 17

What type of muscles are in the orbit?

Answer 17

Mainly striated muscles
- 1 smooth muscle component in the Levator palpebrae superioris muscle

Question 18

What is the action of the Medial rectus?

Answer 18

Adducts the eyeball

Question 19

What is the innervation of the Superior, Inferior, and Medial rectus?

Answer 19

Oculomotor nerve

Question 20

What is the action of the Lateral rectus?

Answer 20

Abducts the eyeball

Question 21

What is the innervation of the Lateral rectus?

Answer 21

Abducent nerve

Question 22

What is the origin of the Superior oblique muscle?

Answer 22

Body of Sphenoid

Question 23

What is the insertion of the Superior oblique muscle?

Answer 23

Tendon passes through a fibrous ring (trochlea) at supero-medial angle of orbital wall

Question 24

What is the innervation of the **Superior oblique muscle**?

Answer 24

**Trochlear** nerve

Question 25

What is the action of the **Superior oblique muscle**?

Answer 25

**Abducts** and **depresses**

Question 26

What is the action of the **Inferior oblique muscle**?

Answer 26

**Abducts** and **elevates**

Question 27

What is the "Chemical formula" for the muscles of the eye?

Answer 27

3(LR6 SO4)

Question 28

What is the function of the Long ciliary nerves?

Answer 28

Carry **sensory** fibres to cornea

Question 29

What is the function of the Short ciliary nerves?

Answer 29

Carries **postganglionic parasympathetic fibres** to the **sphincter pupillae** and **ciliary muscles**

Question 30

Which Cranial nerves run through the Cavernous sinus?

Answer 30

- Oculomotor - Trochlear - Trigeminal (V1 and V2) - Abducens

Question 31

Which structure connects the Auricle to the hearing apparatus?

Answer 31

External auditory meatus/tube

Question 32

List the structures in the Outer Ear

Answer 32

- **Auricle** (Sensory supply V3 Auriculotemporal nerve) - **External auditory meatus**: extends to the **Tympanic** membrane

Question 33

What are the glands in the External Ear and what do they produce?

Answer 33

Cereuminous and sebaceous glands produce **cerumen** (earwax)

Question 34

List the structures in the Middle Ear

Answer 34

- Malleus - Incus - Stapes - Tensor tympani - Stapedius - Auditory Tube

Question 35

List the structures in the Internal Ear

Answer 35

- Bony labyrinth - Vestibule - Oval window - Cochlea - Round window

Question 36

Which nerve is the Internal Ear supplied by?

Answer 36

Vestibulocochlear