Head and Neck

Question 1

Describe the layers of the scalp

Answer 1

Skin
Connective tissue (dense) - nerves and blood vessels
Aponeurosis
Loose connective/areolar tissue - emissary veins traverse this layer
Pericranium

Question 2

List the cutaneous nerves of the scalp

Answer 2

Posterior aspect - cervical spinal nerves (greater, lesser, third occipital nerves)
Anterior aspect - V1
Anterior temporal region - V2
Posterior temporal region - V3

Question 3

Describe the distribution of scalp dermatomes

Answer 3

C2 around parietal region
C3 around posterosuperior of neck
V1 anterior (roughly 2/3rds)
V2 anterior aspect of temporal scalp
V3 posterior aspect of temporal scalp (to tip of ear)

Question 4

Describe the arterial supply and venous drainage of the scalp

Answer 4

Superficial temporal - emerges on the face between TMJ and ear and ends in scalp by dividing into frontal and parietal regions
Occipital and posterior auricular arteries in their respective regions
- all branch directly from ECA

Superficial temporal vein drains forehead/scalp and receives tributaries from veins of the temple and face
Near auricle, the superficial temporal vein enters the parotid gland, joining the maxillary vein to form the retromandibular.
Other superficial veins include occipital, posterior auricular, supraorbital and supratrochlear veins
Deep temporal veins drain into the pterygoid venous plexus

Question 5

Describe the cutaneous innervation of the face

Answer 5

Forehead/medial nose - V1
Cheek/upper jaw - V2
Lower jaw/anterior ear - V3

Neck/behind ear - C2/3

Question 6

Describe the course of arteries which supply the face and the veins which drain it

Answer 6

Facial artery provides major supply to superficial face

• arises from ECA, travels to inferior border of mandible, anterior to masseter, travels up to medial angle of eye
• branches superior and inferior labial

Maxillary artery branches from ECA around external auditory meatus level

The facial vein provides primary superficial drainage
- drains into internal jugular

Question 7

List the main muscles of facial expression and their function
How are they innervated?

Answer 7

Occipitofrontalis - elevates eyebrows
Orbicularis oculi - closes eyelids
Oribuclaris oris - tonus closes mouth, phasic creates kissing motion
Buccinator - preses cheek against molar teeth
Platysma - depresses mandible against resistance

Facial nerve innervation

Question 8

What movements are deficient if facial nerve is damaged?

Answer 8

UMN - weakness of lower part of face, contralaterally
- brow furrowing, eye closure, blinking largely unaffected

LMN - complete ipsilataral weakness of all facial expression muscles
- taste often impaired