Lecture 1 - General Organisation of the Head & Neck

Question 1

How is the head organised?
What are the 2 main groups muscles are organised into?
What blood vessels supply the face?

Answer 1

• Cranium is split into neurocranium & viscerocranium, face is forehead down to chin, scalp is forehead all the way to back of head.
• Muscles split into muscles of facial expression and muscles of mastication (4)
• Facial artery & vein

Question 2

What nerve supplies muscles of facial expression?

What nerve supplies muscles of mastication?

Answer 2

• Facial nerve (CN7)

- Trigeminal nerve (CN5)

Question 3

What are the 5 extra-cranial branches of the facial nerve that supplies muscles of facial expression?
What are they named in accordance to?

Answer 3

• Temporal, Zygomatic, Buccal, Marginal & Cervical (To Zanzibar, By Motor Car)
• The region they supply

Question 4

What are the 3 main branches of the trigeminal nerve that supply sensory to the face?

Answer 4

1) Va ophthalmic division
2) Vb maxillary division
3) Vc mandibular division (also provides motor function to muscles of mastication in mandible)

Question 5

What 3 major branches of the arch of the aorta supply the supply the head and neck with blood?

What 2 vessels does this first branch then form?

What 2 vessels does the second brand bifurcate into?

Answer 5

1) Right brachiocephalic vein
2) Left common carotid artery (for left side)
3) Left subclavian artery (supplies left arm)

Right brachiocephalic vein becomes right external jugular and right common carotid.

L common carotid bifurcates into internal and external carotid artery

Question 6

Locate the sternocleidomastoid and the platysma.

What are the roles of the SCM and the platysma & what are they innervated by?

Answer 6

Locate on 3D anatomy model.

SCM = Rotates head to side and laterally flexes neck. Innervated by accessory nerve (CN11) 
Platysma = Depresses angles of mouth, tenses skin to neck. Innervated by facial nerve (CN7)

See workbook page 19 for pics

Question 7

Locate the trapezius and scalene muscles

What are their roles and their innervations?

Answer 7

Locate on 3D anatomy model.

Trapezius = elevate shoulders (shrugs) and provide shoulder abduction above 90 degrees. Innervated by accessory nerve.

Scalene muscles = anterior, posterior & middle scalene muscles elevate first rib and flex/laterally bend neck to same side. Innervated by cervical spinal nerves.

Question 8

Locate the supra and infra-hyoid muscles

What are their roles?

Answer 8

Locate on 3D anatomy model (above + below hyoid bone)

Suprahyoid = elevate hyoid bone during swallowing
Infrahyoid = depress hyoid bone, mandible and larynx during swallowing and speech

Question 9

What are the anatomical borders of the anterior triangle of the neck?

What are the anatomical borders of the posterior triangle of the neck?

Answer 9

1) Medial border is imaginary midline in the neck
2) Lateral borders are the front edge of the SCM
3) Top border is the bottom of the mandible (see slide 21)

1) Medial border is SCM
2) Lateral border is trapezius
3) Bottom border is clavicle (see slide 22)

Question 10

What are the anatomical borders of the carotid triangle

Answer 10

1) Medial border is superior belly of omohyoid
2) Lateral border is SCM
3) Top border is posterior belly of digastric (see slide 29)

The carotid triangle is a smaller triangle within anterior triangle.

Question 11

What does the cylindrical compartments created by concentrated fascial layers in the neck allow for?

What clinical problem is created by this compartmentalisation?

Answer 11

• Ease of movement between structures (slide over each other without friction) e.g.: when swallowing.
• Spread of deep neck space infections into the mediastinum (as DNP communicate with mediastinum) which can lead to mediastinitus (causes problems to organs, blood vessels in the area + difficulty swallowing). Get through via the retropharyngeal space.

Question 12

Name + Identify the fascial layers and other structures in a cross section of the neck (infrahyoid view)

Answer 12

See page 17 in workbook, need to be able to identify:

• Superficial fascia
• Investing layer, pre-tracheal, carotid sheath & pre-vertebral fascia.
• Buccal-tracheal fascia (back portion of pre-tracheal) & retro-pharyngeal space
• Infrahyoid muscles, SCM, trachea, oesophagus + platysma
• Common carotid artery, internal jugular vein and vagus nerve
• Cervical vertebra, ligamentum nuchae + spinal cord