Superficial face and muscles of facial expression

Question 1

What is the cutaneous nerve supply of the face? (broad and branches)

Answer 1

TRIGEMINAL NERVE
CNV1 - supraorbital, supratrochlear, infratrochlear, external nasal, lacrimal
CNV2 - zygomaticotemporal, zygomaticofacial, infra-orbital
CNV3 - auriculotemporal, buccal, mental

Also, skin over angle of mandible is the greater auricular nerve (C2 & C3)

Question 2

What nerve supplies the back of the head?

Answer 2

The greater occipital (from C2)

Question 3

What nerves supplies the lateral side of neck (over SCM)?

Answer 3

The greater auricular and the lesser occipital (from cervical plexus)

Question 4

What are the 5 main facial expression muscles?

Answer 4

Orbicularis oculi (palpebral and orbital parts)
Orbicularis oris
Buccinator
Platysma
Occipitofrontalis

Question 5

Describe the course of the facial nerve

Answer 5

Enters skull - internal acoustic meatus
Gives greater petrosal branch - innervates the lacrimal gland
Before exiting - Nerve to stapedius and chorda tympani.
Exits skull at stylomastoid foramen
Gives digastric branch and posterior auricular nerve (innervates posterior belly of occipitofrontalis and auricular muscles)
Enters partoid to give off 5 terminal branches

Question 6

What does the temporal branch of CNVII supply?

Answer 6

frontal belly of occipitofrontalis and orbicularis oculi

Question 7

What does zygomatic branch of CNVII supply?

Answer 7

Orbicularis oculi and upper lip muscles

Question 8

What does buccal branch of CNVII supply?

Answer 8

Buccinator and orbicularis oris

Question 9

What does mandibular branch of CNVII supply?

Answer 9

orbicularis oris

Question 10

What does the cervical branch of CNVII supply?

Answer 10

Platysma

Question 11

What are the branches of the facial artery?

Answer 11

Superior labial artery
Inferior labial artery
Lateral nasal arteris
Angular artery - terminal branch of facial

Question 12

What is the intermediate tendon of the occipitofrontalis?

Answer 12

Epicranial aponeurosis

Question 13

What does the occipitofrontalis muscle do?

Answer 13

Wrinkles the forehead (frontal) and retracts the scalp (occipital)

Question 14

What is the insertion of the frontal belly of occipitofrontalis and what is the clinical impplication of this?

Answer 14

Skin/ subcutaneous tissue of eyebrows and forehead.
No bony attachment means infection can spread anteriorly into the face through loose connective tissue.
Posterior, superior nuchal attachment prevents spread of infection in the occipital region.

Question 15

Where does the parotid duct run?

Answer 15

Travels across masseter then pierces buccinator.

Question 16

What is the orbicularis oculi action?

Answer 16

To close eyelids

Question 17

What is orbital part of orbicularis aculi action?

Answer 17

close TIGHTLY, VOLUNTARY

Question 18

What is palpebral part of orbicularis oculi function?

Answer 18

close GENTLY - blinking, INVOLUNTARY blinking reflex

Question 19

What is unique about external facial veins?

Answer 19

No valves in them - blood flows in both directions.
Profuse bleeding if facial vein is cut/ injured.

Question 20

Origin and insertion of orbicularis oris?

Answer 20

Origin - buccinator/ surrounding muscles & medial mandible & maxilla
Insertion - mucous membrane of the lips

Question 21

Action of the orbicularis oris

Answer 21

Clos or protrude the lips

Question 22

What muscle works with orbicularis oris to keep food between occlusal surfaces of teeth?

Answer 22

Buccinator

Question 23

Origin and insertion buccinator

Answer 23

Origin - alveolar processes of mandible/ maxilla & pterygomandibular raphe
Insertion - merge with fibres of orbicularis oris

Question 24

Actions of buccinator

Answer 24

Puff cheeks
Push cheeks against molar teeth, keeps food on occlusal surfaces

Question 25

Origin and insertion of the platysma

Answer 25

origin - subcutaneous tissue of infra and supraclavicular regions
Insertion - base of mandible to merge with orbicularis oris, skin of cheek, lower lip & angle of mouth

Question 26

Action of platysma

Answer 26

Tense the skin of inferior face/ neck and depress the mandible

Question 27

What is generally the venous drainage of the face?

Answer 27

Facial vein drains most of face into IJV.
very variable person to person.

Question 28

What generally drains the upper part of the face?

Answer 28

Transverse facial vein.

Question 29

What can result from the venous drainage of the danger triangle of the face and why?

Answer 29

Skin infections can spread from the face into the small caverns of the cavernous sinus where the pathogens multiply.
Infections spread from facial veins and the pterygoid plexus, because there is no deep fascia and subcutaneous tissue is loose - space to travel.
Can lead to cavernous thrombosis or infections spreading intracranially to the meninges.