S1) General Organisation of the Head & Neck

Question 1

Describe the anatomical location of the neck

Answer 1

The neck extends from the lower margin of the mandible to the suprasternal notch of the manubrium and the upper border of the clavicle below

Question 2

Which nerve innervates the trapezius?

Answer 2

Accessory nerve

Question 3

A series of muscles attach above and below the hyoid bone.

Identify them and their nerve supply

Answer 3

• Supra‐hyoids supplied by cranial nerves
• Infra‐hyoids supplied by cervical nerves (C1‐3)

Question 4

Identify the origins and attachments of the platysma

Answer 4

• Origin: lower mandible
• Attachment: chest wall

Question 5

What are the actions and properties of the platysma?

Answer 5

• Property: superficial (lies in superficial cervical fascia) right under skin
• Action: depresses the corners of the mouth and draw down the mandible

Question 6

The platysma is a muscle of facial expression.

In light of this, which nerve innervates it?

Answer 6

Facial nerve

Question 7

Describe the origins and attachments of the sternocleidomastoid muscle

Answer 7

• Origin: mastoid process
• Attachment: sternum (sternal branch) and clavicle (clavicular branch)

Question 8

What are the actions of the sternocleidomastoid muscle?

Answer 8

• Lateral flexion of the neck
• Head rotation
• Tilting chin up contralaterally

Question 9

Which nerve innervates the sternocleidomastoid muscle?

Answer 9

Accessory nerve

Question 10

Which muscle is contracted in the condition torticollis?

Answer 10

Sternocleidomastoid

Question 11

What are the origins and attachments of the trapezius?

Answer 11

• Origins: external occipital protuberance and superior nuchal line
• Attachments: spine of scapula & lateral 1/3 of clavicle

Question 12

What are the actions of the trapezius?

Answer 12

• Elevation of the shoulders (shrug)
• Rotate and retract the scapula

Question 13

What happens when the accesory nerve is damaged?

Answer 13

Muscle wasting of the trapezius

Question 14

The trapezius is innervated by the accesory nerve. How do we test the function of this nerve?

Answer 14

Test the actions of the trapezius muscle (shrug shoulders)

Question 15

The anatomical borders divide the neck into two triangles.

Which borders form the anterior triangle?

Answer 15

• Inferior margin of the mandible
• Midline of the neck
• Anterior margin of sternocleidomastoid

Question 16

The anatomical borders divide the neck into two triangles.

Which borders form the posterior triangle?

Answer 16

• Superior margin of clavicle
• Anterior margin of trapezius
• Posterior margin of sternocleidomastoid

Question 17

What are the properties of the infra-hyoid muscles?

Answer 17

• Infra hyoids muscles are ‘strap‐like’ muscles
• They overlie the larynx and thyroid gland

Question 18

What type of muscle is the omohyoid?

Answer 18

Infrahyoid

Question 19

What type of muscle is the digastric muscle?

Answer 19

Suprahyoid muscle

Question 20

Identify the carotid triangle

Answer 20

Question 21

Which muscles form the carotid triangle?

Answer 21

• Omohyoid
• Sternocleidomastoid
• Digastric

Question 22

What are the fascial planes of the neck?

Answer 22

Fascial planes are collections of structures enveloped in concentric fascial layers creating compartments running through the neck

Question 23

What is the function of the cervical fascia?

Answer 23

• Forms natural planes
• Ease of movement between structures
• -* Contains spread of infection

Question 24

What are the two forms of cervical fascia?

Answer 24

- Superficial cervical fascia: loose connective tissue (subcutaneous tissue)

- Deep cervical fascia: dense connective tissue

Question 25

Describe the contents of the superficial cervical fascia

Answer 25

- **S**uperficial blood vessels - **C**utaneous nerves - **A**dipose tissue - **L**ymph nodes - **P**latysma

Question 26

Describe the contents of the deep cervical fascia

Answer 26

- Investing layer (outer) - Carotid sheath - Pre tracheal fascia (intermediate) - Pre vertebral fascia (deep)

Question 27

Describe the superior, inferior and posterior attachments of the investing layer of the deep fascia

Answer 27

- **Superior**: lower border of the mandible, mastoid process, superior nuchal line and external occipital protuberance - **Inferior**: upper border of manubrium, clavicle, acromion and spine of scapula - **Posterior**: spinous process of the vertebrae and ligamentum nuchae

Question 28

Describe the superior and inferior attachments of the pretracheal fascial layer

Answer 28

- **Superior**: hyoid bone - **Inferior**: blends with fibrous pericardium in thorax

Question 29

The pretracheal fascia consists of two layers. Identify them and the structures they enclose

Answer 29

- **Muscular layer** which encloses the infrahyoid muscles - **Visceral layer** which encloses the thyroid gland, trachea and oesophagus

Question 30

What is the buccopharyngeal fascia and where is it found?

Answer 30

- The **buccopharyngeal fascia** is the posterior continuation of the pretracheal fascia to invest the muscles of the pharynx, larynx and oesophagus - It extends from the base of the skull to the diaphragm

Question 31

What is the carotid sheath and where is it found?

Answer 31

The **carotid sheath** is a fibrous structure which extends from the base of the skull inferiorly to the aortic arch

Question 32

What are the contents of the carotid sheath?

Answer 32

- Common carotid artery - Internal jugular vein - Vagus nerve (CN X)

Question 33

Describe the anatomical location of the prevertebral fascia

Answer 33

- Extends from the base of the **cranium** to the **T3 vertebra** - Extends laterally as the **axillary sheath** that surrounds the axillary vessels and the brachial plexus

Question 34

Identify and describe the two deep neck spaces that communicate with the mediastinum

Answer 34

- **Retropharyngeal space** (between prevertebral & buccopharyngeal fascia) - **Pre-tracheal space** (in front of pretracheal fascia) They extend inferiorly into the mediastinum

Question 35

What is the danger with infections in the deep neck spaces?

Answer 35

Infections in the retropharyngeal and pretracheal spaces can potentially spread inferiorly to involve mediastinal structures (causing **mediastinitus**)

Question 36

Identify the key structures related to the cervical fascia in the cross section of the neck below:

Answer 36

Question 37

What are the two types of muscles of the face?

Answer 37

- Muscles of facial expression - Muscles of mastication (chewing)

Question 38

Compare and contrast between muscles of facial expression and muscles of mastication in terms of action

Answer 38

**- Muscles of facial expression:** many act as dilators and sphinchters (guards a hole and can relax or contract) **- Muscles of mastication:** act to open/close the jaw

Question 39

Which nerve innervates the muscles of facial expression?

Answer 39

Facial nerve (CN VII) - runs through parotid gland so vulnerable to damage from injury of parotid gland.

Question 40

Cranial nerve V is the trigeminal nerve. What are its three branches? (supplies muscles of mastication)

Answer 40

- V₁ **opthalmic** division - V₂ **maxillary** division - V₃ **mandibular** division (V1-3 are also referred to as Va-c)

Question 41

What are the motor and sensory functions of the trigeminal nerve?

Answer 41

- Main **sensory** nerve of the face and scalp - **Motor** innervation to muscles of mastication

Question 42

There are 5 key extra-cranial branches providing motor innervation to the muscles of facial expression. What are they?

Answer 42

- Temporal - Zygomatic - Buccal - Mandibular - Cervical ***Mnemonic: Ten Zombies Bruise My C\*\*k***

Question 43

What is the main artery supply to the head and neck?

Answer 43

**Common carotid artery** is the main arterial supply by its terminal branches: - Internal carotid artery - External carotid artery

Question 44

Compare and contrast the function of the internal and external jugular veins

Answer 44

- **Internal jugular vein (IJV)** provides venous drainage for the head and neck structures mainly - **External jugular vein (EJV)** provides venous drainage for the scalp and face mainly (more superficial)

Question 45

Identify a vein that drains into the internal jugular vein

Answer 45

Facial vein

Question 46

In a patient with a retropharyngeal abscess, what might be expected with the extension of this infection to the deep neck space?

Answer 46

- Difficulty breathing due to tracheal compression - Extension of infection into the mediastinum - Painful or difficulty swallowing due to oesphageal compression

Question 47

How can one test the function of the trigeminal nerve?

Answer 47

Ask the patient to open their mouth whilst you apply resistance under the jaw – note any deviation (jaw will deviate to side of lesion)

Question 48

How can one test the function of the facial nerve?

Answer 48

- Assess patient's face for any asymmetry - Ask the patient to perform facial expressions and assess power of movements

Question 49

What are the muscles of mastication?

Answer 49

- Temporalis (temples) - Masseter (corner of jaw as you clench) - Lateral pterygoid \**lie deep so can't palpate*\* - Medial pterygoid

Question 50

State the action and innervation of the temporalis muscle

Answer 50

- **Action:** elevates and retracts the mandible (lower jaw muscle) at TMJ - **Innervation:** mandibular branch (branch of trigeminal nerve)

Question 51

State the action and innervation of the masseter muscle

Answer 51

- **Action:** elevates the mandible at TMJ (stronger than medial pterygoid) - **Innervation:** mandibular nerve (branch of trigeminal nerve)

Question 52

State the action and innervation of the lateral and medial pterygoids

Answer 52

- **Action of lateral pterygoids:** protract the mandible, ‘side to side’ movement of the jaw - **Action of medial pterygoids:** elevates mandible at TMJ **- Innervation:** mandibular nerve (branch of trigeminal nerve) * **Originiate:** pterygoid plates on base of skull

Question 53

State the action and innervation of the buccinator muscle

Answer 53

- **Action**: flattens cheek & prevents food from pooling between cheek and gums - **Innervation**: buccal branch of facial nerve

Question 54

State the action and innervation of orbicularis oculi

Answer 54

- **Action:** inner **palpebral** part gently closes the eyelid, outer **orbital** part forcefully closes the eyelid - **Innervation:** temporal and zygomatic branch of facial nerve

Question 55

State the action and innervation of the orbicularis oris

Answer 55

- **Action:** closes mouth (pouts) helps keep fluid inside oral cavity **- Innervation:** buccal branch of facial nerve

Question 56

The occipitofrontalis (frontalis and occipitalis) and its aponeurosis form one of the layers of the scalp. State its action and innervation

Answer 56

- **Action**: elevates eyebrows - **Innervation**: frontal belly (temporal branch of facial nerve) and occipital belly (posterior auricular branch)

Question 57

State the action and innervation of levator palpebrae superioris

Answer 57

- **Action**: elevates upper eyelid - **Innervation**: oculomotor nerve

Question 58

What is Bell's palsy?

Answer 58

- **Bell's palsy** is the inflammation of the facial nerve causing oedema and compression of the nerve as it runs through its bony canal within the temporal bone - This causes facial paralysis on the ipsilateral side of the injury

Question 59

Where can the facial pulse be palpated?

Answer 59

The pulse of the **facial artery** can be palpated as the artery winds around the inferior border of the mandible, just under the jaw

Question 60

What are the main neck muscles

Answer 60

* Sternocleidomastoid * trapezius

Question 61

relevance of scalene Muscles

Answer 61

* accessory muscles of respiration * form floor of posterior triangle * critical structures passing through : brachial plexus and subclavian muscles passing between anterior and middle * phrenic nerve runs along anterior

Question 62

carotid triangle

Answer 62

formed from supra and infra hyoid muscles * digastric * omohyoid

Question 63

muscles involved in depressing the mandible (lower jaw)

Answer 63

* infrahyoids * lateral pterygoid

Question 64

occipitofrontalis

Answer 64

* made up of frontal and occipital belly joined by aponeurosis * causes eyebrow contraction

Question 65

what are the dilators of the mouth?

Answer 65

* risorius * zygomaticus Both draw the the mouth superiorly and posteriorly to smile

Question 66

Where is the parotid gland located in the face?

Answer 66

Question 67

what are all the muscles of mastication and what are they innervated by

Answer 67

* lateral pterygoid * middle pterygoid * temporalis * masseter all inverted by the mandibular division of the trigeminal nerve

Question 68

role of the suprahyoid muscles

Answer 68

he suprahyoid muscles are a group of four muscles located above the hyoid bone in the neck, and they primarily function to elevate and stabilize the hyoid bone and the larynx during speech and swallowing.

Question 69

what are the supra hyoid muscles innervated by

Answer 69

→ posterior belly of the digastric muscle is innervated by the facial nerve → mylohyoid, geniohyoid, and stylohyoid muscles, are innervated by the hypoglossal nerve

Question 70

Which branch is the same in the facial and trigeminal nerve

Answer 70

mandibular (maxillary does not arise from the facial nerve but from the trigeminal nerve)

Question 71

what complications arise if there is an infection in the pretracheal area

Answer 71

→ difficult to breath due to tracheal compression. → infection can spread to the mediastinum → pain or difficulty swallowing due to oesophageal compression

Question 72

where does the carotid sheath extend to

Answer 72

aortic arch

Question 73

which lymph nodes are deep cervical lymph nodes, lying deep to the investing layer

Answer 73

supraclavicular jugulo-digastric jugulo - omohyoid