Ocular Anatomy 1

Question 1

What bones are the orbit made up of

Answer 1

Frontal
Zygoma
Maxillary
Sphenoid
Ethmoid
Palatine
Lacrimal

Question 2

What bones make up the orbital floor

Answer 2

Orbital plate of the maxilla with contributions from the zygomatic and palatine bones

Question 3

What bones forms the lateral wall of the orbit

Answer 3

Zygomatic bone and greater wing of the sphenoid posteriorly

Question 4

What bones forms the orbital roof

Answer 4

Orbital plate of the frontal bone with contribution from the lesser wing of the sphenoid bone

Question 5

What bones form the medial wall of the orbit

Answer 5

Maxilla, lacrimal, ethmoid and body of sphenoid

Question 6

What bone is the superior orbital fissure in

Answer 6

Between greater and lesser wing of sphenoid bone at orbital apex

Question 7

Volume of orbit

Answer 7

30ml

Question 8

What separates the orbit from the ethmoid air cells

Answer 8

lamina papyrecia

Question 9

What fissures are in the orbit? And where do they join to?

Answer 9

Optic canal - middle cranial fossa
Superior orbital fissure - middle cranial fossa
Inferior orbital fissure - pterygopalatine fossa
Nasolacrimal duct - inferior meatus of the nose
Anterior and posterior ethmoidal foramina - ethmoidal air cells

Question 10

What bone is the optic canal in?
What does the optic canal contain?

Answer 10

Lesser wing of sphenoid

Optic nerve
Ophthalmic artery

Question 11

What does the superior orbital fissure contain

Answer 11

Above the tendinous ring:
Lacrimal nerve (CNV1 - ophthalmic nerve)
Frontal nerve (CNV1 - ophthalmic nerve)
Trochlear nerve (CNIV)
Superior ophthalmic vein

Inside the tendinous ring
Superior division of occulomotor nerve
Inferior division of occulomotor nerve
Nasociliary nerve (From CNV1 - ophthalmic nerve)
Abducens (CNVI) nerve

Outside and below tendinous ring
Inferior ophthalmic vein

Question 12

What does the inferior orbital fissure contain

Answer 12

Branches of maxillary nerve (from CNV2 trigeminal)
Emissary vein connecting ophthalmic vein to the pterygoid plexus
Infraorbital artery and vein
Branches of pterygopalatine ganlgion

Question 13

What do the ethmoidal foramina connect and contain?

Answer 13

Anterior ethmoid foramen at junction of the frontal and ethmoid bones - connects to anterior cranial fossa
Contains anterior ethmoidal artery and nerve

Posterior foramina - contains posterior ehtmoidal nerve and artery supplying ethmoidal sinuses

Question 14

What are the margins of the orbit (supraorbital, infraorbital, lateral, medial)?

Answer 14

Supraorbital - frontal bone
Infraorbital - zygomatic bone, maxilla
Lateral - frontal bone and zygomatic bone
Medial - maxillary process of frontal bone and lacrimal crest of frontal process of maxilla

Question 15

What cells line paranasal sinuses?

Answer 15

Pseudostratified columnar ciliated epithelium

Question 16

What drains into the middle meatus of noise?

Answer 16

Maxillary sinus via hiatus semilunaris
Anterior and middle ethmoidal air cells
Frontal air cells

Question 17

What drains into the superior meatus of nose?

Answer 17

Posterior ethmoidal air cells

Question 18

Where do sphenoidal air cells drain?

Answer 18

Sphenoethmoidal recess

Question 19

What sinuses are present at birth

Answer 19

Ethmoidal and maxillary

Question 20

Where do ethmoidal sinus drain?

Answer 20

Posterior - superior meatus
Anterior and middle - middle meatus

Question 21

Where do paranasal sinuses drain lymph?

Answer 21

Submandibular nodes except sphenoid and posterior ethmoidal which drain to retropharyngeal nodes

Question 22

What is the innervation of the maxillary sinus

Answer 22

Infraorbital nerve (from maxillary of trigeminal CNV2)
Anterior, middle and posterior superior alveolar nerves

Refer pain to upper teeth and skin of cheek

Question 23

What is the innervation of the frontal sinus

Answer 23

Supraorbital nerve (ophthalmic nerve from trigemnial CNV1)
skin of forehead and scalp

Question 24

What is the innervation of the sphenoid sinus

Answer 24

Posterior ethmoidal nerves

Question 25

What is the innervation of the ethmoid sinus

Answer 25

Anterior and posterior ethmoidal nerves and branches of the pterygopalatine ganglion