Head and neck anatomy

Question 1

What are the boarders of the anterior triangle of the neck?

Answer 1

• Midline
• Sternocleidomastoid
• Mandible

Question 2

What are the boarders of the posterior triangle of the neck?

Answer 2

• Sternocleidomastoid
• Clavicle
• Trapezius

Question 3

What 2 muscle groups, 2 key vascular structures and 5 nerves pass are within the anterior triangle of the neck?

Answer 3

Muscle groups:
- Suprahyoid muscles
- Infrahyoid muscles

Vascular structures:
- Common carotid artery (bifurcates in the anterior triangle)
- Internal jugular vein

Nerves:
- Facial (VII)
- Glossopharyngeal (IX)
- Vagus (X)
- Spinal accessory (XI)
- Hypoglossal (XII)

Question 4

The anterior triangle of the neck can be subdivided into 4 triangle. What are these?

Answer 4

1. Carotid triangle
2. Submental triangle
3. Submandibular triangle
4. Muscular triangle

Question 5

What are the main contents of the carotid triangle (subdivision of anterior triangle)?

Answer 5

• Common carotid artery - bifurcates into the internal and external carotid arteries within the carotid triangle)
• Carotid sinus
• Internal jugular vein
• Hypoglossal nerve
• Vagus nerve

Question 6

What is the carotid sinus?

Answer 6

• Dilated portion of the common carotid and internal carotid arteries
• Contains baroreceptors which detect stretch as a measure of blood pressure
• The glossopharyngeal nerve feeds this information to the brain to regulate blood pressure

Question 7

What are 2 key vascular structures that are located in the posterior triangle of the neck? Why are these relevant?

Answer 7

1. External jugular vein
   - Lies superficially so is vulnerable to damage
   - If it is severed (e.g. knife injury), pressure needs to be applied to stop the bleeding and air entry
2. Subclavian vein
   - Often used as a point of access to the venous system, via a central catheter

Question 8

What nerve and nerve plexus are located in the posterior triangle of the neck? What is a major branch of this plexus?

Answer 8

• Spinal accessory nerve (XI)
• Cervical plexus - phrenic nerve is major branch

Question 9

What is a cervical plexus block?

Answer 9

• Used for anaesthesia of the neck area
• Local anaesthetic is injected into the cervical plexus located in the posterior triangle of the neck

Question 10

How can the pharynx be divided?

Answer 10

• Nasopharynx
• Oropharynx
• Laryngopharynx

Question 11

What nerve provided motor innervation to the majority of pharyngeal muscles?

Answer 11

Vagus nerve

Question 12

What are 3 functions of the larynx?

Answer 12

• Phonation
• The cough reflex
• Protection of the lower respiratory tract

Question 13

What spinal levels does the larynx span?

Answer 13

C3-C6

Question 14

How can the larynx be divided?

Answer 14

• Supraglottis
• Glottis
• Subglottis

Question 15

What epithelium is the larynx lined by? What is the exception?

Answer 15

• Pseudostratified ciliated columnar epithelium
• True vocal cords are lined by stratified squamous epithelium

Question 16

What epithelium is the larynx lined by? What is the exception?

Answer 16

• Pseudostratified ciliated columnar epithelium
• True vocal chords are lined by stratified squamous epithelium

Question 17

What nerves innervate the larynx?

Answer 17

• Recurrent laryngeal nerve
• Superior laryngeal nerve

Both branches of the vagus nerve. Both have motor and sensory functions

Question 18

Vocal cord paralysis:
1. What nerve is normally affected?
2. Give 4 causes of paralysis of this nerve
3. How might unilateral paralysis present?
4. What is a risk with bilateral paralysis?

Answer 18

1. Recurrent laryngeal nerve
2. Apical lung tumour, thyroid cancer, aortic aneurysm, cervical lymphadenopathy
3. Hoarseness of voice
4. Airway compromise requiring emergency surgical intervention