Face, Scalp, Parotid Gland

Question 1

Layers of the scalp

Answer 1

S- skin
C- connective tissue (dense) - contains vessels and nerves
A- aponeurosis epicranius (galea aponeurotica)
L- loose CT - allows free movement of scalp; plane of cleavage for injury
P- pericranium (periostium)

Question 2

Innervation to the scapl: Spinal nerves

Answer 2

a. Greater occipital n (C2 dorsal ramus)
b. C3 (dorsal ramus)
c. Lesser occipital n
d. Greater auricular n

Question 3

Innervations to the scalp: Cranial Nerves

Answer 3

a. Auriculotemporal branch V3
b. Zygomaticotemporal branch of V2
c. Supraorbital branch of V1
d. Supratrochlear branch of V1

Question 4

Arterial supply to the scalp: from External Carotid

Answer 4

a. Occipital a
b. Posterior auricular a
c. Superficial temporal a

Question 5

Arterial supply to the scalp: from Internal Carotid

Answer 5

a. Supraorbital a

b. Supratrochlear a

Question 6

Venous drainage of the scalp

Answer 6

1. Vena comitantes of arteries
2. Emissary veins - drain through bones of skull to dural venous sinuses
   - Emissary veins are valveless and may spread infections from the scalp to the intracranial cavity

Question 7

General features of muscles of facial expression

Answer 7

a. All are derived from pharyngeal arch 2
b. All are innervated by CN VII (SVE component)
c. All are superficial muscles which can move the skin and fascias of the face

Question 8

Orbicularis oculi

Answer 8

a. Orbital part - surrounds orbit and forcefully closes eye
b. Palpebral portion - within eyelid; gently closes eye
c. Lacrimal portion - within medial corner of eye; assists with lacrimal fluid drainage

Question 9

Currugator supercilli

Answer 9

draws eyebrows down and in (worried look)

Question 10

Occipitofrontalis

Answer 10

a. Frontal and occipital bellies attached by epicranial aponeurosis
b. Frontal belly - elevates eyebrows; wrinkles forehead
c. Occipital belly - retracts scalp; assists frontal belly in “surprised” expression

Question 11

Muscles associated with the mouth

Answer 11

a. Orbicularis oris - closes lips/mouth
b. Buccinator - keeps cheeks in contact with gums so food doesn’t accumulate in vestibule of the mouth.
c. Levator labii superioris - elevates upper lip
d. Levator anguli oris - elevates upper lip; widens mouth
e. Zygomaticus major - elevates upper lip; main smile muscle
f. Zygomaticus minor - elevates upper lip
g. Risorius - stretches lips laterally; wide smile
h. Levator labii superioris alaeque nasi - elevates upper lip; flare nostrils
i. Depressor anguli oris - depresses lower lip; frown
j. Depressor labii inferioris - depresses lower lip; frown; pout
k. Mentalis - protrudes lower lip

Question 12

Muscles associated with the nose

Answer 12

a. Procerus - wrinkles skin over dorsum of nose (dislike)

b. Nasalis - flares nostrils

Question 13

Facial nerve: SVE to all mm of facial expression

Answer 13

1. Exits the brainstem
2. Enters internal acoustic meatus
3. Courses laterally between cochlea and semicircular canals, after which it bends posteriorly and inferiorly to course along posterior wall of the middle ear
4. Exits facial canal via stylomastoid foramen

Question 14

Branches of the Facial nerve

Answer 14

1. Post. auricular n - supplies belly of occupitofrontalis
2. Digastric n
3. Stylohyoid n
4. Temporofacial trunk (temporal, zygomatic, buccal branches)
5. Cervicofacial trunk (buccal, marginal mandibular, cervical branches)

Question 15

Facial (Bell’s) Nerve Paralysis

Answer 15

1. Causes - many are idiopathic; links to herpes virus, trauma or lesion anywhere along course of nerve, otitis media
2. Paralysis of mm of facial expression
3. Facial asymmetry and drooping
4. Drooping of lower eyelid causes drainage of tears and ulceration of eye
5. Paralysis of orbicularis oris causes dribbling of saliva
6. Loss of buccinator leads to accumulation of food within vestibule
7. Impaired speech

Question 16

Cutaneous Inn to Face: Opthalmic n (V1)

Answer 16

a. Supplies embryonic frontonassal prominence
b. Provides skin of forehead, upper eyelid, nose

Branches

1. Supratrochlear n
2. Supraorbital n
3. Lacrimal n
4. Infratrochlear n
5. External nasal n

Question 17

Cutaneous Inn to Face: Maxillary n (V2)

Answer 17

a. Supplies embryonic maxillary prominence
b. Provides skin of temporal region, upper cheek and lip, lower eyelid, ala of nose

Branches

1. Zygomaticotemporal n
2. Zygomaticofacial n
3. Infraorbital n

Question 18

Cutaneous Inn to Face: Mandibular n (V3)

Answer 18

a. Provides embryonic mandibular prominence
b. Provides skin of lower cheek, lower lip, and chin

Branches

1. Auriculotemporal n
2. Buccal n
3. Mental n

Question 19

Cutaneous Inn to Face: Great auricular n (C2, C3)

Answer 19

Provides skin over angle of mandible

Question 20

Trigeminal Neuralgia (tic douloureux)

Answer 20

a. Sensory disorder of trigeminal nerve which causes sudden, excruciating facial pain
b. Cause is believed to be demyelination of axons within sensory root of CN V; in some cases due to compression by superior cerebellar a.
c. Divisions affectes: V2 > V3 > V1

Question 21

Nerve blocks for facial/dental surgery

Answer 21

a. Infraorbital n - anesthetic agent injected around infraorbital foramen; accessed by inserting needle through superior portion or oral vestibule.
b. Mental n - anesthetic agent injected around the mental foramen on the chin
c. Buccal n - anesthetic agent injected via the oral vestibule just posterior to the 3rd mandibular molar

Question 22

Herpes Zoster Infection

Answer 22

Often affects the trigeminal ganglion. It most often affects V1 and can lead to scarring/ulceration of cornea

Question 23

Facial artery course

Answer 23

1. Branches from ext carotid a. within submandibular triangle
2. Courses through substance of submandibular gland
3. Arches over mandible just anterior to masseter to enter face
4. Takes tortuous course to allow for movement of face; course along angle of mouth, then along lateral side of nose medial to angle of eye

Question 24

Branches of the Facial Artery

Answer 24

1. Inferior labial a
2. Superior labial a
3. Lateral nasal a
4. Angular a

Question 25

Superficial temporal artery

Answer 25

``` a. Branch of ext carotid Branches 1. Transverse facial artery 2. Frontal branches 3. Parietal branches ```

Question 26

Maxillary artery

Answer 26

``` a. Branch of ext carotid Branches 1. Infraorbital a 2. Buccal a 3. Mental a ```

Question 27

Ophthalmic a

Answer 27

``` a. Branch of int carotid Branches 1. Supraorbital a 2. Supratrochlear a 3. Lacrimal (lateral palpebral) a 4. Medial palpebral a 5. Dorsal nasal a ```

Question 28

Venous drainage of the face: Retromandibular vein

Answer 28

a. Formed from union of superficial temporal and maxillary veins b. Courses posterior to ramus of mandible within substance of parotid gland c. Divides into anterior and posterior divisions d. Anterior division merges with facial vein e. Posterior division merges with posterior auricular vein to form ext jugular

Question 29

Facial vein

Answer 29

a. Begins at medial corner of eye as angular vein; descend face receiving venae comitantes of artery b. Joins anterior division of retromandibular vein to form the common facial vein which drains to int jugular c. Communicates with deeper plexuses 1. With pterygoid plexus via deep facial vein 2. With cavernous sinus via ophthalmic veins 3. Clinical correlation: the central face is a "danger area" for an infection to travel into the skull or into the deep face

Question 30

Lymphatic drainage of the face

Answer 30

1. Lymphatic vessels of the face drain to submental, submandibular, and parotid lymph nodes 2. Ultimately, lymph flow is to deep cervical lymph nodes along int jugular

Question 31

Parasympathetic preganglionic innervation to the face

Answer 31

1. Location of cell bodies - salivatory nucleus w/in brainstem 2. Pregang fibers travel with CN IX 3. CN IX exits jugular foramen and immediately gives a tympanic branch 4. The tympanic nerve then enters the middle ear via tympanic canaliculus 5. Travels through the middle ear, then reforms as the lesser petrosal nerve 6. Lesser petrosal nerve exits middle ear via hiatus for lesser petrosal; nerve is now in middle cranial fossa and exits via foramen ovale 7. Lesser petrosal n is now in infratemporal fossa and synapses in otic ganglion

Question 32

Parasympathetic postganglionics in face

Answer 32

1. Location of cell bodies - otic ganglion | 2. Postgang fibers travel with auriculotemporal branch of V3

Question 33

Sympathetic innervation to the face

Answer 33

a. Pregang symp cell bodies in SC T1-T4 b. Postgang symp cell bodies in superior cervical sympathetic ganglion c. Postgang fibers travel with ext carotid nerve to parotid tissue d. Function: vasomotor

Question 34

Parotiditis

Answer 34

Refers to inflammation of parotid gland. Very painful bc of stretching of parotid sheath. Pain from parotid region is carried via auriculotemporal branch of V3 and the great auricular nerve. Often, pain will "refer" to the auricle, TMJ, and ext acoustic meatis.

Question 35

Sialolith (calculus)

Answer 35

A calcified concretion that can sometimes form in the parotid gland. If it passes into the parotid duct, the duct can become blocked.