T1L8 orbit and nasal cavity

Question 1

nose

4 bones

3 main cartilages

divider

3 internal lateral projection

nasal cavity opens into __

nerve supply

Answer 1

bones:

• paired nasal
• maxillae
• frontal bone
• septum

cartilages:

• major
• alar
• septal

septum divides 2 nasal cavities

nasal cavity opens into nasopharynx

nerve supply:

• olfactory
• ophthalmic

Question 2

CN1 olfactory

Answer 2

type: special afferent sensory
exit: cribiform plate

Question 3

olfaction

Answer 3

• air flows through nasal cavity
• conchae warm and moisten air
• olfaction receptors line roof and walls
• epithelium secrete a mucus fluid. odoriferous gases are dissolved in the fluid and then detected by the olfactory nerves

Question 4

paranasal sinuses

Answer 4

• air filled extensions of nasal cavity
• 2 frontal sinuses in frontal bone (drain through frontonasal duct)
• sphenoidal sinuses in sphenoid bone that drain into spheno-ethmoidal recess
• paired maxillary sinuses in maxilla drain into middle meatus or superior meatus

Question 5

orbit

7 bones

Answer 5

• frontal
• maxilla
• ethmoidal
• lacrimal
• sphenoidal
• temporal-zygomatic
• nasal

Question 6

eye

3 layers

Answer 6

1. outer fibrous (sclera and cornea)
2. vascular (iris)
3. inner (retina)

Question 7

CN2 optic

Answer 7

type: special afferent sensory
exit: optic canal

special embryology- optic stalk

Question 8

movement of the eye: 7

Answer 8

7 extraocular muscles

• levator palpebrae
• superior oblique
• superior rectus
• medial rectus
• lateral rectus
• inferior rectus
• inferior oblique

Question 9

3 axis of eye movement

Answer 9

• vertical
• transverse
• anteroposterior

Question 10

what each eye muscle does

Answer 10

inferior oblique - up and lateral

lateral rectus - lateral

superior oblique - down and lateral

superior rectus - up and medial

medial rectus - medial

inferior rectus- down and medial

s15

Question 11

cranial nerve 3 oculomotor

Answer 11

type: somatic motor to extra-ocular muscles (except superior oblique and lateral rectus) and short ciliary nerves to ciliary body and sphincter pupillae

ie.

• 4 eye movement muscles
• pupil contraction
• ciliary body (lens)

exit: superior orbital fissure

Question 12

CN4 trochlear

Answer 12

type: somatic motor to superior oblique
exit: superior orbital fissure

Question 13

CN6 abducent

Answer 13

type: somatic motor to lateral rectus
exit: superior orbital fissure

Question 14

orbit blood supply

Answer 14

• ophthalmic artery
• infra-orbital artery
• central artery

Question 15

crying

Answer 15

• lacrimal gland (orbital and palpebral parts) secretes lacrimal fluid which passes across eye into lacrimal papilla, lacrimal sac and to the inferior meatus via the nasolacrimal duct

parasympathetic- CN7 facial

sympathetic- superior cervical ganglion via internal carotid