The orbit

Question 1

which bone forms the roof of the orbit?

Answer 1

frontal

Question 2

which bone forms the floor of orbit?

Answer 2

zygomatic

Question 3

which nerves pass through the superior orbital fissure?

Answer 3

CN III, CNIV, CNV1

Question 4

eyelids - layers

Answer 4

skin
connective tissue
muscle
orbital septum
tarusus
conjunctiva

Question 5

Tarsus - function

Answer 5

eyelid support (superior and inferior)

Question 6

preseptal cellulitis features

Answer 6

• infection of skin anterior to orbital septum
  important to differentiate between orbital cellulitis

Question 7

orbital cellulitis features

Answer 7

infection posterior to orbital septum
pain on movements of eye that are restricted
bulging of eye
threatens vision
risk of infection spread to cavernous sinus or meninges of brain

Question 8

conjunctivitis features

Answer 8

also known as pink eye
inflammation of membrane covering posterior surface of eyelid and eyeball

Question 9

eyelids - sensory innervation

Answer 9

CN V1 and CN V2

Question 10

Eyelids - arterial supply

Answer 10

external carotid (facial, transverse facial, superficial temporal)
and internal carotid (supratrochlear, supraorbita, lacrimal)

Question 11

lacrimal gland parasympathetic supply

Answer 11

pregangioèic fibres from facial nerve from CN VII nervous intermedium
travel in greater petrosal n the nerve of pterygoid canal
arrive in pterygopalatine ganglion
postganglionic fibres hitch huge to zygomatic branch of CN V2 to reach lacrimal gland

Question 12

lateral rectus innervation

Answer 12

CN VI - abducens

Question 13

Superior oblique muscle innervation

Answer 13

CN IV - trochlear

Question 14

which muscle is responsible for raising the superior eyelid?

Answer 14

levator palpebrae superioris