Superficial muscles of the face

Question 1

Describe briefly the cutaneous nerve supply of the face and scalp?

Answer 1

Motor innervation of the face is via CN VII
Sensory innervation- angle of the mandible is supplied via great auricular nerve (C2 and C3 via cervical plexus) and rest of the face via CN V

Question 2

Describe the attachments, nerve supply and action of orbicularis oculi

Answer 2

Palpebral part:
- origin= medial palpebral ligament
- insertion= lateral palpebral raphe at the ligament
Orbital part:
- origin= nasal part of frontal bone, frontal process of maxilla and medial palpebral ligament
- insertion= skin around margin/ orbit

nerve supply- temporal and zygomatic branch CN VII

action- gently close eyelid, involuntary (palpebral), tightly close eyelid, voluntary (orbital)

Question 3

Describe the attachments, nerve supply and action of orbicularis oris

Answer 3

origin- buccinator/ surrounding muscles and medial mandible/ maxilla
insertion- mucous membrane of lips

nerve supply- mandibular branch CN VII

action- keeps food between occlusal surfaces of teeth

Question 4

Describe the attachments, nerve supply and action of buccinator

Answer 4

origin- posterior part of alveolar process of maxilla/ mandible and pterygomandibular raphe
insertion- merge with fibres of orbicularis oris

nerve supply- buccal branch CN VII

action- puff cheeks out, smiling, presses cheeks against molars, keeps food within occlusal surfaces and out of oral vestibule

Question 5

what is a buccal fat pad?

Answer 5

buccal fat pad is much larger in children to reinforce cheeks when feeding- associated with chubby cheeks
lies superficial to buccinator and is pierced by parotid duct

Question 6

Describe the attachments, nerve supply and action of platysma

Answer 6

origin- subcutaneous tissue of infra and supraclavicular regions
insertion- base of mandible to merge with orbicularis oris

Question 7

Describe the attachments, nerve supply and action of occipitofrontalis?

Answer 7

frontal belly:
origin- epicranial aponeurosis
insertion- subcutaneous tissue of eyebrows and forehead

occipital belly:
origin- lateral 2/3 of superior nuchal line
insertion- epicranial aponeurosis

nerve supply- frontal= temporal branch, occipital= posterior auricular branch CN VII

action- wrinkle forehead, raise eyebrows, retract scalp

Question 8

what is the function of superior nuchal line

Answer 8

prevents spread of infection

Question 9

what is the action of dilator muscles around the mouth?

Answer 9

to widen, lift or depress the corners of the mouth

Question 10

give examples of dilator muscles of the mouth

Answer 10

levator anguli oris, depressor anguli oris
zygomaticus major
zygomaticus minor
levator labii superioris
depressor labii inferioris
mentalis

Question 11

Which muscle is responsible for wrinkling nose?

Answer 11

procerus and transverse part of nasalis

Question 12

which muscle is responsible for flaring nostrils?

Answer 12

nasalis, together with levator labii superioris and alaeque nasi

Question 13

describe the innervation, arterial supply and venous drainage of muscles of the ears?

Answer 13

innervation- CN VII
arterial supply- ECA via posterior auricular and superficial temporal arteries
venous drainage- EJV

Question 14

Why do facial wounds tend to bleed a lot?

Answer 14

facial wounds tend to bleed a lot as the terminal branches of ICA and ECA anastomose in the midline (as well as veins)

Question 15

Where can a pulse be taken in the face?

Answer 15

from transverse facial artery, anterior to auricle

superficial temporal artery where it crosses zygomatic process anterior to auricle

facial pulse can be palpated when someone clenches their teeth- where facial artery crosses inferior border of mandible immediately anterior to masseter muscle

Question 16

which vein drains most of upper face

Answer 16

Transverse facial vein drains most of the upper face

Question 17

From which 2 veins is the retromandibular vein formed?

Answer 17

retromandibular vein is formed by the joining of the superficial temporal and maxillary vein

Question 18

describe the course of retromandibular vein

Answer 18

runs posterior to ramus and emerges from parotid gland inferiorly- dividing into anterior branch (unites with facial vein) and posterior branch (to EJV as it joins with posterior auricular vein)

Question 19

what is the ‘danger triangle’?

Answer 19

from the corners of mouth to bridge of nose
infection here can travel into cavernous sinus, slow blood flow can cause severe infection - thrombosis spreads intercranially to meninges

Question 20

why do facial wounds tend to gape open?

Answer 20

facial wounds tend to gape open as the face has no distinct deep fascia- subcutaneous tissue between the cutaneous attachment of facial muscles is loose. blood can accumulate in the face leading to inflammation

Question 21

What is the innervation of the ears?

Answer 21

All innervated by the CN VII

Question 22

what is the blood supply of the ears?

Answer 22

ears are supplied by the ECA via posterior auricular and superficial temporal arteries

Question 23

what structure joins the eyelids together at each angle?

Answer 23

the palpebral fissure

Question 24

describe the structure of the eyelid?

Answer 24

covered externally by skin, internally by transparent mucous membrane (conjunctiva) which is loosley attached to sclera
-skin
-connective tissue
-conjunctiva
- muscle
- tarsus
- orbital septum

Question 25

what is the orbital septum?

Answer 25

orbital septum = fibrous membrane from tarsi to margins of orbit when becomes continuous with periosteum of bone - can limit spread of infection from orbit

Question 26

what is the blood supply of the eyelids?

Answer 26

blood supply of eyelids= ECA via facial, transverse facial, superficial temporal and ICA via supratrochlear, supraorbital and lacrimal

Question 27

what is the purpose of lacrimal fluid?

Answer 27

lacrimal fluid keeps cornea moist

Question 28

what is the innervation of the eylids?

Answer 28

innervation of the eyelid comes from CN V1 and V2 (sensory) and motor via temporal and zygomatic branches of CN VII