Week 3 - WET

Question 1

Name 3 foramina in the orbit of the eye.

Answer 1

Optic foramen

Superior orbital fissure

Inferior orbital fissure

Question 2

What passes through the optic foramen?

Answer 2

Optic nerve

Opthalmic artery

Question 3

What passes through the superior orbital fissure?

Answer 3

III nerve

IV nerve

V₁ nerve

VI nerve

Opthalmic veins

Question 4

What passes through the inferior orbital fissure?

Answer 4

V₂ nerve

Question 5

Name the 3 layers of the eyeball

Answer 5

Fibrous layer

Vascular layer

Sensory layer

Question 6

Name the 2 components of the fibrous layer.

Answer 6

Cornea

Sclera

Question 7

Name the components of the vascular layer

Answer 7

Choroid

Ciliary body

Iris

Question 8

Name the component of the inner sensory layer

Answer 8

Retina

Question 9

What structure divides the eye into an anterior and posterior segment?

Answer 9

Lens

Question 10

What is the name given to the watery fluid in the anterior segment?

Answer 10

Aqueous humour

Question 11

What is the name given to the gel in the posterior segment?

Answer 11

Vitreous humor

Question 12

What part of the eye secretes aqueous humor?

Answer 12

Ciliary body

Question 13

Name the 3 intrinsic muscles of the eye

Answer 13

Ciliaris (muscle of ciliary body)

Sphincter (constrictor) pupillae

Dilator pupillae

Question 14

What is the function of the ciliaris muscle?

Answer 14

Change shape of lens = accomodation

Question 15

What is the function of the sphincter pupillae?

Answer 15

Constric pupil

Question 16

What is the innervation to the sphincter pupillae?

Answer 16

Parasympathetic - Cr. N III (occulomotor)

Question 17

How is the sphincter pupillae arranged around the pupil?

Answer 17

Circularly

Question 18

What is the function of the dilator pupillae?

Answer 18

Dilate pupil

Question 19

What is the innervation to the dilator pupillae?

Answer 19

Sympathetic innervation

Question 20

How are the fibres of the dilator pupillae arranged within the iris?

Answer 20

Radially arranged - like spokes on a wheel

Question 21

Name the 7 extrinsic muscles of the eyes.

Answer 21

Superior, inferior, lateral, medial recti

Superior and inferior obliques

Levator palpebri superiorus

Question 22

What is the innervation for each of the 7 extrinsic muscles of the eye? Be specific.

Answer 22

Superior oblique - IV (trochlear)

Lateral rectus - VI (abducens)

All the rest - III (oculomotor)

(SO4, LR6, AR3)

Question 23

What is the action of the medial rectus?

Answer 23

Adduction

Question 24

What is the action of the lateral rectus?

Answer 24

Abduction

Question 25

What are the 3 actions of the superior rectus?

Answer 25

Elevation, adduction, intorsion RADSIN

Question 26

What are the 3 actions of the inferior rectus?

Answer 26

Depression, adduction, extorsion

Question 27

What are the 3 actions of the superior oblique?

Answer 27

Depression, abduction, intorsion

Question 28

What are the 3 actions of the inferior oblique?

Answer 28

Elevation, abduction, extorsion

Question 29

What is the only extrinsic muscle of the eye which doesnt arise from the posterior aspect of the orbit?

Answer 29

Inferior oblique

Question 30

Name the ligaments which prevent over-adduction or over-abduction of the eye?

Answer 30

Medial and lateral check ligaments

Question 31

What is the function of the suspensory ligaments of the eye?

Answer 31

Suspend lens from ciliary body

Question 32

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

Answer 32

Opthalmic artery

Question 33

Through which foramen does the opthalmic artery enter the orbit?

Answer 33

Optic foramen

Question 34

Which foramina in the orbit do the opthalmic veins pass through to enter into the carvernous venous sinus?

Answer 34

Superior orbital fissure

Question 35

Name the 3 ossicles.

Answer 35

Malleus, incus, stapes

Question 36

Which ossicle is in contact with the tympanic membrane?

Answer 36

Malleus

Question 37

Which ossicle is in contact with the oval window?

Answer 37

Stapes

Question 38

Name 2 muscle related to the ossicles.

Answer 38

Stapedius Tensor tympani

Question 39

What is the function of the stapedius?

Answer 39

Stablises stapes bone.

Question 40

What is the function of the tensor tympani?

Answer 40

Dampen loud sounds (by **tensing** tympanic membrane)

Question 41

Name 2 areas with which the middle ear cavity communicates.

Answer 41

Nasopharynx (via eustachin tube aka pharyngotympanic tube) Mastoid air cells

Question 42

Within which part of the temporal bone do the inner and middle ear lie?

Answer 42

Petrous part

Question 43

Inner ear = bony labyrinth and membranous labyrinth. What are each of these?

Answer 43

Bony labyrinth: **rigid, bony outer wall** of the inner ear in the temporal bone. Membranous labyrinth: **fluid filled tubes (endolymph)** which contain **receptors** for hearing and balance. It lies **within** the bony labyrinth, surrounded by **perilymph**

Question 44

What fluid lies within the bony labyrinth?

Answer 44

Perilymph

Question 45

What fluid lies within the membranous labyrinth?

Answer 45

Endolymph

Question 46

Through which foramen does the facial nerve exit the posterior cranial fossa?

Answer 46

Internal acoustic meatus.

Question 47

Which other cranial nerve exits through this foramen?

Answer 47

VIII - vestibulocochlear

Question 48

While in the middle ear cavity, the facial nerve gives off the chorda tympani. State 2 things this will go and innervate.

Answer 48

Sub-mandibular and sub-lingual salivary glands. Anterior 2/3rds of tongue - taste sensation