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

basically, vagus nerve + the arteries/veins going up towards the neck (so not the subclavian)

Question 5

What are the contents of the visceral fascia? (pretracheal 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 (continuous with pretracheal)

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. c1 b. C2 c. C3 d. C4 e. C6 f. C7

Answer 8

a. C1 opening of mouth b. C2 Superior cervical ganglion c. C3 Body of hyoid d. C4 Bifurcation of common carotid Upper border of thyroid cartilage (laryngeal prominence/adams apple) e. C6 Cricoid cartilage Middle cervical ganglion f.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? (anterior triangle contains supra and infra hyoid muscles) What are the main arteries and veins in the anterior triangle?

Answer 10

Platysma – facial VII (NOT SUPRA OR INFRAHYOID)

SUPRAHYOID:

Mylohyoid (fan shaped muscle) – mandibular division of trigeminal (V) = V3

Digastric muscle (2 bellies)– anterior belly (mandibular division of trigemina V3l) + posterior belly (facial)

Geniohyoid= a thin strap shaped muscle that is superior to the fan shaped mylohyoid muscle (additional content added)

Stylohyoid= next to the digastric muscle, this is between stylous process and the hyoid bone (additional content) I

INFRAHYOID:

4 Infrahyoid muscles (strap muscles)

ARTERIES/VEINS: carotid arteries and internal jugular vein

Question 11

Which nerves innervate each of the four infrahyoid muscles? What are the attachments for each muscle?

Answer 11

Just remember that thyrohyoid is the odd one out

Omohyoid (scapula/shoulder area to hyoid bone) – ansa cervicalis

Sternohyoid (sternum to hyoid bone) – ansa cervicalis

Sternothyroid (sternum to thyroid cartilage) – ansa cervicalis

THYROHYOID (thyroid cartilage to hyoid bone) – C1 fibres via the hypoglossal nerve

Just remember that thyro

Question 12

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

Answer 12

Veins:

External jugular vein

Subclavian vein

Artery: Subclavian artery

Nerve:

Trunks of brachial plexus

Phrenic nerve and other nerves from cervical plexus

Vagus nerve

Spinal accessory nerve (spinal component of the accessory nerve)

Question 13

Which other smaller nerves from the cervical plexus are found in the posterior triangle, along with the phrenic?

Answer 13

Lesser occipital nerve: cutaneous branch from cervical plexus that innervates skin of the neck and scalp posterior and superior to the auricle (the ear)

Greater auricular nerve : from cervical plexus, provides sensory innervation for the skin over parotid gland and mastoid process, and surfaces of the outer ear.

Transverse cervical nerve: cutaneous branch of the cervical plexus that innervates the skin covering the anterior cervical region.

Supraclavicular nerves: from the cervical plexus that supply the skin over the upper medial part of the chest.

Question 14

Where do the trunks of the brachial plexus emerge?

Answer 14

Posterior to scalenus anterior (scalene has anterior, medius and posterior parts)

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 Brachial plexus Roots= c5-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 (VII) (cervical branch)

Question 20

What is mylohyoid innervated by?

Answer 20

Mandibular division of trigeminal (V) nerve V3

Question 21

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

Answer 21

Anterior – mandibular division of trigeminal nerve (V3) Posterior – facial nerve (VII)

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

Describe the course of the accessory nerve

Answer 27

Spinal portion: - arises from upper spinal cord (c1-c5/6) -fibres from these roots join together and then enter the skull via foramen magnum (part of posterior cranial fossa) - goes to the jugular foramen and briefly MEETS THE CRANIAL PORTION before exiting via jugular foramen - after exiting, it descends along with internal carotid a. and then it reaches SCM and trapezius which it innervates CRANIAL PORTION: - arises from medulla oblongata - leaves via jugular foramen (where it briefly contacts with spinal portion) - after exiting, it joins with vagus nerve - hence a lot of the nerve supply of accessory is done THROUGH THE VAGUS. (vagus contains fibres from accessory basically)

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 shoulder shrugs=work ur traps traps are innervated by accessory nerve

Question 30

What are the four infrahyoid muscles and where are they attached?

Answer 30

4 infra hyoid muscles:

Omohyoid – superior border of scapula near scapular notch –> hyoid

Sternohyoid – sternum –> hyoid

sternothyroid – sternum –> thyroid cartilage

Thyrohyoid – thyroid cartilage –> hyoid NB some diagrams draw sternothyroid and thyrohyoid as a single continuous muscle from the hyoid bone to the sternum but it is supposed to be divided into these two components

Question 31

Can you name any other suprahyoid muscles? (not mentioned in slides but mentioned by anatomy zone and worth remembering)

Answer 31

Additional suprahyoid muscles: Geniohyoid= a thin strap shaped muscle that is superior to the fan shaped mylohyoid muscle Stylohyoid= next to the digastric muscle, this is between stylous process and the hyoid bone

Question 32

what does genio- prefix mean when talking about muscles

Answer 32

attached to the chin part of the mandible

Question 33

what plexus is the ansa cervicalis part of? What does the name ansa cervicalis mean

Answer 33

cervical plexus. Ansa= handle cervicalis= neck handle of the neck

Question 34

ansa cervicali has a loop shape, what are its superior and inferior roots?

Answer 34

Since it is loop shaped (U shape), at one end of the U, the roots come from C1. On the other end of the U, the roots come from C2 and C3. The end with roots from C1 is termed superior root (because it is C1 which is superior to C2 and c3) The other end with roots from C2 and C3 is called inferior root