Orbit and nasal cavity

Question 1

What are the bones of the nasal cavity

Answer 1

Nasal bones, maxillae, frontal bone and septum

Question 2

What are the cartilages that form the nasal cavity

Answer 2

• Lateral
• Major alar
• Septal

Question 3

What are the three projections of the internal lateral wall and what is their purpose?

Answer 3

• Superior conchae
• Middle conchae
• Inferior conchae
• help direct flow of air through nose

Question 4

What does the nasal cavity open into?

Answer 4

Nasopharynx

Question 5

Arterial supply of the nose

Answer 5

Branches from ophthalmic and maxillary

Question 6

Nerve supply of nose

Answer 6

Olfactory nerve, ophthalmic(v1 and maxillary v2) trigeminal vein

Question 7

Where are olfaction receptors located

Answer 7

• Epithelium lining the roof and walls of the nasal cavity

Question 8

How does olfaction occur

Answer 8

• Epithelium secretes a mucus fluid, odoriferous gases are dissolved into the fluid and then detected by the olfactory nerves

Question 9

What is anosmia

Answer 9

Partial or complete loss of sense of smell

Question 10

What are paranasal sinuses

Answer 10

• Paranasal sinuses are air filled extensions of the nasal cavity

Question 11

Where do the paired frontal sinuses drain into?

Answer 11

• Each one opens into anterior part of the middle nasal meatus through which the frontonasal duct which traverses the anterior part of the ethmoid labyrinth

Question 12

What are ethmoidal cells

Answer 12

• Ethmoidal cells are invaginations in the ethmoid bone and drain into middle meatus(if anterior, or middle) or superior meatus(if posterior)

Question 13

What do the sphenoidal sinuses in sphenoid bone drain into?

Answer 13

• Sphenoidal sinuses drain into spheno-ethmoidal recess

Question 14

Where do paired maxillary sinuses drain into?

Answer 14

• Middle meatus

Question 15

What is the notch on the frontal bone for?

Answer 15

• Cutaneous nerve

Question 16

What are the three layers of the eye?

Answer 16

Outer fibrous - Sclera and cornea

Vascular - iris

Inner - retina

Question 17

How do eyes develop

Answer 17

• Optic stalk grows out and lens vesicle grows in

Question 18

What are the 7 extraocular muscles surrounding the globe of the eye and therefore responsible for moving it?

Answer 18

• Levator palpebrae superioris(elevates the eyelid)
• Superior oblique
• Superior rectus
• Medial rectus
• Lateral rectus
• Inferior rectus
• Inferior oblique

Question 19

What are the three different axes for rotation of the eye

Answer 19

• Anteroposterior (lateral-medial rotation)
• Transverse axis (elevation-depression)
• Vertical axis (abduction-adduction)

Question 20

What does the superior rectus do?

Answer 20

• Active in elevation of the eye(also inwards)
• Also draws it towards midline(adduction)
• Top of the eye

Question 21

What does the inferior rectus do?

Answer 21

• Bottom of the eye

- Active in depression of the eye(also inwards)

Question 22

What does the medial rectus do?

Answer 22

• Adduction

Question 23

What does the lateral rectus do?

Answer 23

• Abduction

Question 24

What does the superior oblique do?

Answer 24

• Attached to the superior part of the eye

- Down and outwards directional movement

Question 25

What does the inferior oblique do?

Answer 25

- Attached to the inferior part of the eye | - Upwards and out directional movement

Question 26

What is the type of innervation provided by cranial nerve 3 - oculomotor

Answer 26

- Somatic motor(general somatic efferent) to extra-ocular muscles(except-superior oblique and lateral rectus) and (general visceral efferent-parasympathetic) via cillary nerves to cillary body and sphincter pupillae

Question 27

Effect of parasymp and smp on the eye

Answer 27

- Parasymp constricts eye | - Symp dilates eye

Question 28

What is the type of innervation provided by cranial nerve 4 - trochlear

Answer 28

- Somatic motor(general somatic efferent) to superior oblique

Question 29

What is the type of innervation provided by cranial nerve 6 - abducent

Answer 29

- Somatic motor(general somatic efferent) to lateral rectus

Question 30

What nerves are compromised when specific eye movements are impaired?

Answer 30

CN 3, 4 and 6

Question 31

What nerve is likely to be compromised when the pupil is dilated

Answer 31

- CN 3

Question 32

What nerve is likely to be compromised in ptosis(drooping or falling of upper eyelid)?

Answer 32

- CN 3

Question 33

Damage to what nerve can cause an abnormal pupil reflex?

Answer 33

- CN3

Question 34

What are the main nerves supplying the eye

Answer 34

- CNII, III, IV, V1, VI, VII

Question 35

Blood supply for the eye

Answer 35

- Ophthalmic - Infra-orbital - Cerebral

Question 36

What nerve can be damaged by an aneurysm of cerebral artery?

Answer 36

- CN3

Question 37

What nerve can be damaged by an orbital fracture

Answer 37

- CN4

Question 38

What nerve can be damaged by an cavernous sinus lesion?

Answer 38

- CN6

Question 39

What does the lacrimal apparatus consist of?

Answer 39

- Lacrimal gland(two parts, orbital and palpebral)

Question 40

What does the lacrimal gland secrete lacrimal fluid into?

Answer 40

- Lacrimal papilla - Lacrimal sac - Inferior meatus via nasolacrimal duct

Question 41

Nerve supply to the lacrimal gland

Answer 41

- Parasympathetic - secretomotor(via facial VII) | - Sympathetic - vasoconstrictive(superior cervical ganglion, via internal carotid)