Session 3: Neck and Face

Question 1

What are the three main functions of the neck?

Answer 1

Structural – support and move the head
Visceral functions
Conduit for blood vessels and nerves

Question 2

How are the components of these functions divided structurally in the neck?

Answer 2

Structural – inside prevertebral fascia
Visceral – inside or associated with pretracheal fascia
Blood vessels and nerves – carotid sheaths

Question 3

What are the two large muscles that are found on the anterior and posterior sides of the neck?

Answer 3

Anterior – sternocleidomastoid

Posterior – trapezius

Question 4

What are the contents of the carotid sheath?

Answer 4

Internal jugular vein
Common carotid artery
Vagus nerve

Question 5

What are the contents of the visceral fascia?

Answer 5

Oesophagus
Trachea
Thyroid Gland

Question 6

What is the name given to the fascia between the posterior aspect of the oesophagus and the anterior part of the prevertebral fascia?

Answer 6

Buccopharyngeal fascia

Question 7

Which fascia splits in two around the sternocleidomastoid and trapezius?

Answer 7

Investing layer

Question 8

What important structures are at each of the following levels:

a. C2
b. C3
c. C4
d. C6
e. C7

Answer 8

a. C2
Superior cervical ganglion
b. C3
Body of hyoid
c. C4
Birfurcation of common carotid  
Upper border of thyroid cartilage
d. C6
Cricoid cartilage 
Middle cervical ganglion
e.C7
Inferior cervical ganglion

Question 9

What are the two triangles of the neck? State their borders.

Answer 9

Anterior triangle – mandible, anterior border of sternocleidomastoid and midline
Posterior triangle – posterior border of sternocleidomastoid, anterior border of trapezius and clavicle

Question 10

What are the main muscles in the anterior triangle and which nerves innervate them?
What are the four infrahyoid muscles and where are they attached?

Answer 10

Platysma – facial
Mylohyoid – mandibular division of trigeminal
Digastric muscle – anterior belly (mandibular division of trigeminal) + posterior belly (facial)
Infrahyoid muscles (strap muscles)
Omohyoid – superior border of scapula near scapular notch –> hyoid
Sternohyoid – sternum –> hyoid
Sternothyroid – sternum –> thyroid cartilage
Thyrohyoid – thyroid cartilage –> hyoid

Question 11

Which nerves innervate each of the four infrahyoid muscles?

Answer 11

Omohyoid – ansa cervicalis
Sternohyoid – ansa cervicalis
Sternothyroid – ansa cervicalis
THYROHYOID – C1 fibres via the hypoglossal nerve

Question 12

The posterior triangle consists mainly of blood vessels and nerves. Which blood vessels and nerves are in the posterior triangle?

Answer 12

External jugular vein  
Subclavian artery 
Trunks of brachial plexus  
Phrenic nerve  
Spinal accessory nerve

Question 13

Which other smaller nerves are found in this area?

Answer 13

Lesser occipital nerve
Greater auricular nerve
Transverse cervical nerve
Supraclavicular nerves

Question 14

Where do the trunks of the brachial plexus emerge?

Answer 14

Posterior to scalenus anterior

Question 15

Where are the subclavian artery and vein relative to the scalene muscles?

Answer 15

Subclavian artery = posterior to scalenus anterior

Subclavian vein = anterior to scalenus anterior

Question 16

Where is the phrenic nerve relative to the scalene muscles?

Answer 16

Phrenic nerve lies on the anterior surface of scalene anterior

Question 17

Which spinal nerves contribute to the superior, middle and inferior trunks of the brachial plexus?

Answer 17

Superior = C5 + C6 
Middle = C7 
Inferior = C8 + T1

Question 18

Which spinal nerves contribute to the phrenic nerve and what isits main function?

Answer 18

C3, C4 and C5
Motor supply of the diaphragm
Sensory innervation to the diaphragmatic pleura and peritoneum

Question 19

What is platysma innervated by?

Answer 19

Facial nerve (cervical branch)

Question 20

What is mylohyoid innervated by?

Answer 20

Mandibular division of trigeminal nerve

Question 21

What are the anterior and posterior bellies of the digastric muscle innervated by?

Answer 21

Anterior – mandibular division of trigeminal nerve

Posterior – facial nerve

Question 22

What are the infrahyoid muscles innervated by?

Answer 22

Ansa cervicalis = omohyoid + sternothyroid + sternohyoid C1 fibres via hypoglossal nerve = thyrohyoid

Question 23

What are the clinical applications of a carotid pulse?

Answer 23

Measuring pulse rate

Question 24

List the main sites of access for central venous lines.

Answer 24

Internal jugular (most common)
Subclavian vein
Femoral vein

Question 25

What are the uses of central venous lines?

Answer 25

Long-term access e.g. for chemotherapy drugs
Administering drugs that can cause phlebitis
Parenteral nutrition
Monitoring blood pressure

Question 26

What are the complications of insertion of central venous lines?

Answer 26

Accidental arterial puncture  
Tracheal injury 
Arrhythmia 
Emboli 
Infection  
Pneumothorax or haemothorax

Question 27

Where does the accessory nerve exit the skull?

Answer 27

The accessory nerve begins in the upper spinal cord and ascends to enter the skull through the foramen magnum
The accessory nerve then leaves via the jugular foramen

Question 28

What does the accessory nerve innervate?

Answer 28

Trapezius

Sternocleidomastoid

Question 29

How would you test the function of the accessory nerve?

Answer 29

Ask the patient to shrug their shoulders and hold it there