S1) General Organisation of the Head & Neck Flashcards Preview

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Flashcards in S1) General Organisation of the Head & Neck Deck (59)
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1
Q

Describe the anatomical location of the neck

A

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

2
Q

Which nerve innervates the trapezius?

A

Accessory nerve

3
Q

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

Identify them and their nerve supply

A
  • Supra‐hyoids supplied by cranial nerves
  • Infra‐hyoids supplied by cervical nerves (C1‐3)
4
Q

Identify the origins and attachments of the platysma

A
  • Origin: lower mandible
  • Attachment: chest wall
5
Q

What are the actions and properties of the platysma?

A
  • Property: superficial (lies in superficial cervical fascia)
  • Action: depresses the corners of the mouth and draw down the mandible
6
Q

The platysma is a muscle of facial expression.

In light of this, which nerve innervates it?

A

Facial nerve

7
Q

Describe the origins and attachments of the sternocleidomastoid muscle

A
  • Origin: mastoid process
  • Attachment: sternum (sternal branch) and clavicle (clavicular branch)
8
Q

What are the actions of the sternocleidomastoid muscle?

A
  • Lateral flexion of the neck
  • Head rotation
  • Tilting chin up contralaterally
9
Q

Which nerve innervates the sternocleidomastoid muscle?

A

Accessory nerve

10
Q

Which muscle is contracted in the condition torticollis?

A

Sternocleidomastoid

11
Q

What are the origins and attachments of the trapezius?

A
  • Origins: external occipital protuberance and superior nuchal line
  • Attachments: spine of scapula & lateral 1/3 of clavicle
12
Q

What are the actions of the trapezius?

A
  • Elevation of the shoulders (shrug)
  • Rotate and retract the scapula
13
Q

What happens when the accesory nerve is damaged?

A

Muscle wasting of the trapezius

14
Q

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

A

Test the actions of the trapezius muscle (shrug shoulders)

15
Q

The anatomical borders divide the neck into two triangles.

Which borders form the anterior triangle?

A
  • Inferior margin of the mandible
  • Midline of the neck
  • Anterior margin of sternocleidomastoid
16
Q

The anatomical borders divide the neck into two triangles.

Which borders form the posterior triangle?

A
  • Superior margin of clavicle
  • Anterior margin of trapezius
  • Posterior margin of sternocleidomastoid
17
Q

What are the properties of the infra-hyoid muscles?

A
  • Infra hyoids muscles are ‘strap‐like’ muscles
  • They overlie the larynx and thyroid gland
18
Q

What type of muscle is the omohyoid?

A

Infrahyoid

19
Q

What type of muscle is the digastric muscle?

A

Suprahyoid muscle

20
Q

Identify the carotid triangle

A
21
Q

Which muscles form the carotid triangle?

A
  • Omohyoid
  • Sternocleidomastoid
  • Digastric
22
Q

What are the fascial planes of the neck?

A

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

23
Q

What is the function of the cervical fascia?

A
  • Forms natural planes
  • Ease of movement between structures
  • -* Contains spread of infection
24
Q

What are the two forms of cervical fascia?

A

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

- Deep cervical fascia: dense connective tissue

25
Q

Describe the contents of the superficial cervical fascia

A
  • Superficial blood vessels
  • Cutaneous nerves
  • Adipose tissue
  • Lymph nodes
  • Platysma
26
Q

Describe the contents of the deep cervical fascia

A
  • Investing layer (outer)
  • Carotid sheath
  • Pre tracheal fascia (intermediate)
  • Pre vertebral fascia (deep)
27
Q

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

A
  • 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
28
Q

Describe the superior and inferior attachments of the pretracheal fascial layer

A
  • Superior: hyoid bone
  • Inferior: blends with fibrous pericardium in thorax
29
Q

The pretracheal fascia consists of two layers.

Identify them and the structures they enclose

A
  • Muscular layer which encloses the infrahyoid muscles
  • Visceral layer which encloses the thyroid gland, trachea and oesophagus
30
Q

What is the buccopharyngeal fascia and where is it found?

A
  • The buccopharyngeal fascia is the posterior continuation of the pretracheal fascia to invest the muscles of the pharynx and oesophagus
  • It extends from the base of the skull to the diaphragm
31
Q

What is the carotid sheath and where is it found?

A

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

32
Q

What are the contents of the carotid sheath?

A
  • Common carotid artery
  • Internal jugular vein
  • Vagus nerve (CN X)
33
Q

Describe the anatomical location of the prevertebral fascia

A
  • 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
34
Q

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

A
  • Retropharyngeal space (between prevertebral & buccopharyngeal fascia)
  • Pre-tracheal space (in front of pretracheal fascia)

They extend inferiorly into the mediastinum

35
Q

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

A

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

36
Q

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

A
37
Q

What are the two types of muscles of the face?

A
  • Muscles of facial expression
  • Muscles of mastication
38
Q

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

A

- Muscles of facial expression: many act as dilators and sphinchters

- Muscles of mastication: act to open/close the jaw

39
Q

Which nerve innervates the muscles of facial expression?

A

Facial nerve (CN VII)

40
Q

Cranial nerve V is the trigeminal nerve.

What are its three branches?

A
  • V1 opthalmic division
  • V2 maxillary division
  • V3 mandibular division

(V1-3 are also referred to as Va-c)

41
Q

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

A
  • Main sensory nerve of the face and scalp
  • Motor innervation to muscles of mastication
42
Q

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

What are they?

A
  • Temporal
  • Zygomatic
  • Buccal
  • Mandibular
  • Cervical

Mnemonic: To Zanzibar By Motor Car

43
Q

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

A

Common carotid artery is the main arterial supply by its terminal branches:

  • Internal carotid artery
  • External carotid artery
44
Q

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

A
  • 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)
45
Q

Identify a vein that drains into the internal jugular vein

A

Facial vein

46
Q

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

A
  • Difficulty breathing due to tracheal compression
  • Extension of infection into the mediastinum
  • Painful or difficulty swallowing due to oesphageal compression
47
Q

How can one test the function of the trigeminal nerve?

A

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

48
Q

How can one test the function of the facial nerve?

A
  • Assess patient’s face for any asymmetry
  • Ask the patient to perform facial expressions and assess power of movements
49
Q

What are the muscles of mastication?

A
  • Temporalis
  • Masseter
  • Lateral pterygoid
  • Medial pterygoid
50
Q

State the action and innervation of the temporalis muscle

A
  • Action: elevates and retracts the mandible at TMJ
  • Innervation: mandibular branch (branch of trigeminal nerve)
51
Q

State the action and innervation of the masseter muscle

A
  • Action: elevates the mandible at TMJ (stronger than medial pterygoid)
  • Innervation: mandibular nerve (branch of trigeminal nerve)
52
Q

State the action and innervation of the lateral and medial pterygoids

A
  • 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)

53
Q

State the action and innervation of the buccinator muscle

A
  • Action: flattens cheek & prevents food from pooling between cheek and gums
  • Innervation: buccal branch of facial nerve
54
Q

State the action and innervation of orbicularis oculi

A
  • Action: inner palpebral part gently closes the eyelid, outer orbital part forcefully closes the eyelid
  • Innervation: temporal and zygomatic branch of facial nerve
55
Q

State the action and innervation of the orbicularis oris

A
  • Action: closes mouth

- Innervation: buccal branch of facial nerve

56
Q

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

State its action and innervation

A
  • Action: elevates eyebrows
  • Innervation: frontal belly (temporal branch of facial nerve) and occipital belly (posterior auricular branch)
57
Q

State the action and innervation of levator palpebrae superioris

A
  • Action: elevates upper eyelid
  • Innervation: oculomotor nerve
58
Q

What is Bell’s palsy?

A
  • 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
59
Q

Where can the facial pulse be palpated?

A

The pulse of the facial artery can be palpated as the artery winds around the inferior border of the mandible