Surface anatomy of the neck

Question 1

What is the retropharyngeal space?

Answer 1

• The largest potential space
• Split between the alar fascia
• There is a true Retropharyngeal space which permits the movement of the trachea, oesophagus and larynx during swallowing
• Danger space = posterior to the alar fascia where infection can spread to the mediastinum

Question 2

What are the health problems associated with the retropharyngeal space?

Answer 2

• Danger space = posterior to the alar fascia where infection can spread to the mediastinum
• Retropharyngeal abscesses
• Dental abscesses can spread tot he mediastinum

Question 3

What are the borders of the anterior triangle?

Answer 3

• Superior border: Inferior border of the mandible
• Lateral border: Anterior border of the sternocleidomastoid
• Medial border: Sagittal line down the midline of the neck

Question 4

What are the borders of the posterior triangle?

Answer 4

• Anterior border: Posterior border of the sternocleidomastoid muscle
• Posterior border: Anterior border of the trapezius muscle
• Inferior border: middle 1/3 of the clavicle

Question 5

If a patient has a neck lump, what are the important things to note?

Answer 5

• Location
• Size and depth
• Tenderness
• Movement

Question 6

Where is the parotid gland?

Answer 6

Between the:
• Mastoid process: just behind the ear
• Angle of the mandible: edge of the jaw

Question 7

Which muscles cover the brachiocephalic trunk?

Answer 7

• Right sternohyoid muscle

* Sternothyroid muscle

Question 8

Describe the parts of the subclavian artery

Answer 8

• Medial border of the anterior scalene at the origin of the subclavian artery
- 3 branches: Vertebral artery, thyrocervical trunk, internal thoracic artery

• Posterior to the anterior scalene:
- 1 branch: costocervical trunk

• lateral border of the anterior scalene
- 1 branch: dorsal scapular artery

It then goes on to form the axillary artery

Question 9

What level does the common carotid artery bifurcate at?

Answer 9

The level of the thyroid cartilage (internal and external carotid artery)

Question 10

Describe the covering of the common carotid artery

Answer 10

• Superiorly it is covered by muscles

* Distally it is exposed allowing palpation of the pulse (normally the internal carotid)

Question 11

What is the baroreceptor reflex?

Answer 11

Passing out because you took both of the carotid pulses at the same time

Question 12

Where is the carotid body?

Answer 12

Where the carotid artery is dilated (internal carotid)

Question 13

What is the carotid body?

Answer 13

• Contains special sensory nerves - baroreceptors
• Mainly innervated by glossopharyngeal (becomes carotid sinus nerve) and a bit by the vagus
• Reacts to changes in the arterial blood pressure
• Carotid body is a chemoreceptor (monitors the partial pressure of CO2)

Question 14

What covers the internal carotid artery?

Answer 14

Carotid sheath

Question 15

What does the internal carotid supply?

Answer 15

Intercranial structures - brain

Question 16

What are the branches of the external carotid arteries from inferior to superior?

Answer 16

• Superior thyroid
• Lingual
• Ascending pharyngeal
• Facial
• Occipital
• Posterior auricular
• Superficial temporal and maxillary

Question 17

What are the terminal branches of the external carotid?

Answer 17

• Superficial temporal

* Maxillary

Question 18

What is the venous supply of the head and neck?

Answer 18

• Facial veins 
- superficial 
- deep
• Cervical veins 
- external jugular vein 
- anterior jugular vein 
- vertebral vein 
• Cranial veins 
- cerebral vein
- Dural venous sinuses 
- Diplopic veins 
- emissary veins

Question 19

What are the cranial veins drained by?

Answer 19

• Dural venous sinus 
- superior sagittal sinus
- inferior sagittal sinus
- sinus rectus 
• Sigmoid sinus 
- becomes the internal jugular vein

Question 20

What does the internal jugular vein drain?

Answer 20

Intracranial structures, superficial parts of the head and neck

Question 21

What is a normal central venous pressure?

Answer 21

<8cm on H2O

Question 22

What are the complications of central venous catheterisation

Answer 22

• Pneumothorax
• Puncture of subclavian artery
• Nerve injury

Question 23

Why is the external jugular vein not used?

Answer 23

There is a risk of air embolism

Question 24

What is the external jugular vein formed from?

Answer 24

• Posterior division of the retromandibular vein

* Posterior auricular vein

Question 25

What does the external jugular vein drain?

Answer 25

most of the scalp and the side of the face

Question 26

Describe the route of the external jugular vein

Answer 26

• Descends from the angle of the mandible to the middle of the clavicle
• Crosses the SCM obliquely, deep to the platysma and enters the antero-inferior part of the posterior triangle
• Pierces the investing fascia at the posterior border of the SCM
• Descends and terminates in the subclavian vein

Question 27

Describe the position of the anterior jugular vein

Answer 27

• Inferior to the hyoid bone

* Right and left anterior jugular arteries join to form the jugular venous arch

Question 28

What does the anterior jugular vein drain to?

Answer 28

• External jugular
or
• Subclavian

Question 29

What is Erb’s point?

Answer 29

4 cutaneous branches become superficial 
• Lesser occipital 
• Great auricular 
• Transverse cervical 
• Supraclavicular

Question 30

Accessory nerve

Answer 30

• Motor control of the trapezius and SCM

* Passes across the posterior triangle

Question 31

Lymph nodes in the head

Answer 31

• None in the scalp or face except in the buccal/parotid region
• All drained into the neck