face,scalp, facial nerve

Question 1

what are the layers of scalp?

Answer 1

skin, superficial fascia==>loculated fat(highly vascular), epicranial aponeurosis attaches to superior and temporal nuchal lines, lax areolar tissue/loose fascia (might tear,avascular), pericranium.

Question 2

innervation of muscles of expression and scalp in general?

Answer 2

motor from cutaneous branches of facial nerve.

sensory from cutaneous branches of all the three divisions of the trigeminal nerve.

Question 3

types of salivary glands?

Answer 3

intrinsic and extrinsic.
Intrinsic: within oral mucosa-numerous and small
Extrinsic; outside oral cavity come in via ducts, 3 pairs and large.

Question 4

capsule of the parotid is derived from the — of the neck.

Answer 4

deep cervical fascia

Question 5

what are the attachments of superficial part of parotid capsule?

Answer 5

zygomatic arch, mandible, styloid process and tympanic plate.

Question 6

attachments of deep part of parotid capsule?

Answer 6

styloid process and medial side of angle of mandible. Forms the stylomandibular ligament supporting TMJ.

Question 7

innervation of parotid?

Answer 7

parasymp= glossopharyngeal origin fibres join auriculotemporal nerve as hitchhikers
symp=external carotid plexus
sensory= dual sensory
1. superficial and inferior parts and capsule: greater auricular branch of cervical plexus
2. auriculotemporal-deep and superior parts of gland.

Question 8

structures within parotid gland?

Answer 8

deep to superficial :
external carotid=divides into maxillary and superficial temporal arteries within parotid.
retromandibular vein=superficial temporal and maxillary veins join within parotid to form retromandibular vein.
facial nerve=divides to form cutaneous branches with this region names ‘pes anserinus’.
also 1st part of auriculotemporal nerve.

Question 9

describe the course of greater petrosal nerve?

Answer 9

comes of the geniculate ganglion of facial nerve as parasymp fibres, bends sharply anteromedially across the floor of middle cranial fossa, down to foramen lacerum, joins deep petrosal nerve(symp) to form nerve of pterygoid canal; composite nerve with both pregang symp and parasymp which go to pterygopalatine ganglion. Greater petrosal also carries taste from soft palate.

Question 10

list cutaneous branches of trigeminal divisions.

Answer 10

1.Ophthalmic: supratrochlear, supraorbital from frontal nerve, lacrimal, infratrochlear from nasociliary nerve, external nasal from anterior ethmoidal which itself from nasociliary nerve,
2.Maxillary: zygomatico-orbital
zygomaticofacial, zygomaticotemporal from zygomatic nerve, infraorbital
3.Mandibular: deep/sensory/long buccal, auriculotemporal, mental nerve.

Question 11

facial expression muscles of the forehead?

Answer 11

occipitofrontalis-frontal belly
corregator supercilii-deep to frontalis and orbicularos oculi
used for frowning in conjunction with occipitofrontalis and orbicularis oculi

Question 12

facial expression muscles of the eye?

Answer 12

orbicularis oculi-lifts the eyelid, closes eyes etc.

Levator palpebrae superioris-also lifts the eyelid.

Question 13

facial expression muscles of the nose?

Answer 13

• procerus
• nasalis
• levator labii superioris alaquae nasae

Question 14

muscles of the mouth?

Answer 14

7 muscles that move the corners and insert into modiolis:

1. zygomaticus major-elevates corner of the mouth
2. levator anguli oris-deep to facial vein and z. minor, elevates corner of the mouth
3. buccinator-outer surfaces of maxilla and mandible over molars and pterygomandibular raphe. Positions cheeks, directs food over molars.
4. platysma-body of mandible, to skin over pectoralis. Depresses the lower lip and mouth corners.
5. depressor anguli oris-corners of mouth down
6. orbicularis oris-sphincter of mouth, other muscles converge on it, no direct bony attachments, some fibres derived from buccinator.
7. risorius- moves mouth corner

Question 15

muscles to lift the lip up?

Answer 15

1. levator labii superioris-deep
2. levator labii superioris alaque nasi- also dilates nostrils
3. zygomaticus minor

Question 16

muscles to depress the lip?

Answer 16

1. depressor labii inferioris- medial to depressor anguli oris
2. mentalis; depresses base of lower lip, protrusion and eversion.

Question 17

key features of muscles of facial expression:

1. levator labii superioris alaque nasi(LLSAN)
2. LLS
3. L.anguli oris
4. zygomaticus major and z.minor
5. mentalis and depressor labii inferioris
6. buccinator
7. risorius

Answer 17

1. two heads-one to nostril and one to upper lip, arises beneath orbicularis oris
2. deep and lateral to LLSAN, convergence of two muscles inferiorly
3. very deep, lateral to LLS, deep to z.minor
4. both from zygomaticus bone, both blend with O.oris, but Major to corner of mouth, minor to upper lip.
5. mentalis-fans laterally and upwards
   depressor L.I-arises laterally, converges medially and upwards to blend with o.oris, superficial to mentalis.
6. parotid duct pierces before passing into vestibule, connects to pterygomandibular raphe
7. horizontal

Question 18

where is buccal fat pad located?

Answer 18

between z.major&L.angularis oris AND buccinator. extends along parotid duct, deep to zygomatic arch to lie between temporalis fascia and temporalis muscle.

Question 19

what passes through buccal fat pad?

Answer 19

parotid duct and sensory buccal nerve,

Question 20

blood supply and drainage of parotid gland?

Answer 20

posterior auricular, superficial temporal and transverse facial arteries.
Veins: retromandibular vein.

Question 21

describe the course of parotid duct

Answer 21

leaves anterior border of gland, crosses superficial surface of masseter,pierces upper buccinator and empties into the vestibule.

Question 22

parotid duct walls are —–

Answer 22

fibromuscular

Question 23

what are the roots of facial nerve and what do they innervate

Answer 23

large motor and smaller sensory root
Motor root innervates stapedius+muscles of face, scalp, auricle, anterior neck.
Sensory root/nervus intermedius carries sensory and parasymp fibres. Sensory conveys taste anterior 2/3 and soft palate. Parasymp are secretomotor to submandibular, sublingual and lacrimal glands of palate and nasal mucosa.

Question 24

course of facial nerve?

Answer 24

travels initially with vestibucochlear nerve with nervus intermedius, enter internal acoustic meatus, facial nerve and N.I separate from the CN8 in the meatus, enter facial canal passing horizontally above the vestibule of inner ear, then bends and passes vertically down the medial wall of middle ear.

Question 25

what info fo the sensory fibres of geniculate ganglion carry?

Answer 25

taste from chorda tympani from A.2/3.
taste from soft palate via greater petrosal nerve
cutaneous sensory of skin of ear
parasymp fibres pass through ganglion without synapsing.

Question 26

what are the branches coming off the vertical part of facial nerve within facial canal?

Answer 26

1. motor stapedius
2. chorda tympani, just before stylomastoid foramen, arches upwards, goes across upper part of tympanic membrane, into bone, down to petrotympanic fissure to join lingual nerve. 3. sensory auricular branch-to skin of external acoustic meatus and external ear.

Question 27

what info does chorda tympani carry

Answer 27

taste from a.2/3, parasymp to the submandibular ganglion and then to subman and sublingual glands.

Question 28

branches of facial n. after passing stylomastoid foramen?

Answer 28

1. posterior auricular-to occipital belly of occipitofrontalis
2. small branches to posterior belly of digastric and stylohyoid

Question 29

list the cutaneous branches of facial nerve

Answer 29

1. temporal-occipitofrontalis, orbicularis oculi, corregator supercilii
2. zygomatic- inferior aspect of orbicularis oculi
3. buccal- face between o.oculi and oral fissure which includes: z.major and minor, procerus, nasalis, L.LSAN,LLS,L.anguli oris, buccinator and orbicularis oris.
4. marginal mandibular-muscles of lower lip(depressor anguli oris, DLI, mentalis) and risorius
5. cervical branches-platysma

Question 30

Supraorbital nerve(V) leaves the skull through—- foramen, where —– fibres of —- nerve join it.

Answer 30

supraorbital foramen, proprioceptive fibres of facial nerve join it as hitchhikers to innervate O.Oculi and frontal belly of occipitofrontalis.

Question 31

infraorbital nerve (V2) leaves the skull through—-foramen where —-fibres from facial n. join to go to muscles e.g.—-

Answer 31

infraorbital foramen, proprioceptive fibres join and go to muscles e.g. levator labii superioris alaeque nasi, LLS,z.minor etc.

Question 32

—- hitchhikers from facial n. join the mental nerve to innervate muscles e.g.—-

Answer 32

proprioceptive, mentalis, depressor labii inferioris and depressor anguli oris.