S3) Major Blood Vessels of the Head and Neck

Question 1

What is the anatomical surface landmark that relates to the dotted line A-B in the image below?

Answer 1

Angle of Louis (manubrio-sternal angle)

Question 2

Name the components of the aorta illustrated as H, I and J

Answer 2

• H – ascending aorta
• I – aortic arch
• J – descending aorta

Question 3

Name the blood vessels labelled C, D, E, F and G

Answer 3

• C – Brachiocephalic trunk
• D – Right common carotid artery
• E – Right subclavian artery
• F – Left common carotid artery
• G – Left subclavian artery

Question 4

Which arteries arise from the brachiocephalic trunk on the right hand side?

Answer 4

Subclavian and common carotid arteries

Question 5

Which arteries arise from subclavian artery in the base of the neck?

Answer 5

Question 6

What are the branches of the thyrocervical trunk?

Answer 6

• Suprascapular artery
• Ascending cervical artery
• Inferior thyroid artery
• Transverse cervical artery

Question 7

Which region does the suprascapular artery supply?

Answer 7

Suprascapular artery supplies the shoulder

Question 8

Which region do the ascending and transverse cervical arteries supply?

Answer 8

Ascending cervical and transverse cervical arteries supply the neck

Question 9

Which region does the inferior thyroid artery supply?

Answer 9

Inferior thyroid artery supplies lower pole of the thyroid gland

Question 10

Where do vertebral arteries arise from?

Answer 10

Vertebral arteries arise from the subclavian arteries on left & right

Question 11

Describe the course of the vertebral arteries through the brain

Answer 11

• Ascend in the neck through transverse foramina in C1-6
• They pass through the foramen magnum

Question 12

Describe how the vertebral arteries supply the brain

Answer 12

The vertebral arteries supply the brain along with the internal carotid arteries which enter the skull through the carotid canal

Question 13

Which arteries arise from the common carotid artery?

Answer 13

Common carotid artery bifurcates to give external and internal carotid arteries

Question 14

Where does the common carotid bifurcate?

Answer 14

The common carotid bifurcates at about the level of the superior border of the thyroid cartilage

Question 15

Describe the anatomical position of the internal jugular vein

Answer 15

The internal jugular lies lateral to the common carotid mostly under sternocleidomastoid

Question 16

Bifurcation of the carotid artery is a common site for atheroma formation.

What are the consequences of this?

Answer 16

• Causes stenosis of the artery
• Rupture of the clot can cause an embolus to travel to brain (TIA or stroke)

Question 17

What is the carotid sinus and what does it do?

Answer 17

• Carotid sinus is a swelling at region of bifurcation
• Location of baroreceptors for detecting changes in aBP

Question 18

What is the carotid body?

Answer 18

Carotid body is a group of peripheral chemoreceptors which detect arterial O₂

Question 19

Which neurovascular structures can be accessed through the carotid triangle?

Answer 19

• Carotid arteries
• Internal jugular vein
• Vagus nerves
• Hypoglossal nerves

Question 20

Which pulse can be felt in the carotid triangle?

Answer 20

Carotid pulse can be felt in carotid triangle just below bifurcation

Question 21

What is the carotid sinus massage and what does it do?

Answer 21

• The carotid massage involves gently massaging the carotid artery
• Pressure in the area of carotid sinus quickly reduces heart rate (alleviates supra-ventricular tachycardias)

Question 22

Describe the course of the internal carotid artery through the head and neck

Answer 22

• Enters skull through carotid canal
• Turns medially and horizontally
• Enters the cranial cavity then bends (S-shaped) to course through the cavernous sinus

Question 23

What is the cavernous sinus?

Answer 23

Cavernous sinus is a plexus of extremely thin-walled veins on upper surface of sphenoid

Question 24

Identify 6 neurovascular structures in the cavernous sinus

Answer 24

Question 25

The ophthalmic artery branches from the internal carotid artery. Identify its two main branches

Answer 25

- Supratrochlear artery - Supraorbital artery

Question 26

Identify the 6 branches of the external carotid artery

Answer 26

- **F**acial - **L**ingual - **O**ccipital - **A**scending pharyngeal - **P**osterior auricular - **S**uperior thyroid

Question 27

Identify the two terminal branches of the external carotid artery

Answer 27

- Superficial temporal - Maxillary

Question 28

Describe the nature of the blood supply to the scalp

Answer 28

- Rich blood supply with many anastomoses - Largely branches of external carotid artery

Question 29

Describe the anatomical position of scalp blood vessels

Answer 29

Vessels of the scalp lie in the subcutaneous connective tissue layer

Question 30

Where does the skull get its blood supply from? Why is this significant?

Answer 30

- Mostly **middle meningeal artery,** the terminal branch of the maxillary artery - Hence, loss of blood from scalp does not lead to bone necrosis

Question 31

What are the consequences of a rupture to the skull?

Answer 31

Fracture of skull at pterion can cause the **middle meningeal artery** (supplies skull and dura) to rupture i.e. extradural haemorrhage

Question 32

Where do the superficial arteries of the face arise from?

Answer 32

- All arise from the **external carotid artery** - **Exception**: supra-orbital and supratrochlear artery arise from internal carotid artery

Question 33

Where can the facial pulse be felt?

Answer 33

Facial artery pulse can be felt at **inferior border of mandible**, anterior to the masseter muscle

Question 34

Identify the two most important branches in the nasal septum

Answer 34

- Septal branch of sphenopalatine artery (from maxillary artery) - Anterior ethmoidal arteries (from ophthalmic artery)

Question 35

Why is the Kiesselbach area in the nasal septum a common site for epistaxis?

Answer 35

- Anastomosis of arteries in Kiesselbach area - Hence prone to nose bleeds

Question 36

What is a craniotomy and how is it performed?

Answer 36

- **Craniotomy** is a procedure used to gain access to cranial cavity - The bone and scalp flap are reflected inferiorly to preserve blood supply

Question 37

Identify the 3 superficial veins draining the scalp

Answer 37

- Superficial temporal veins - Occipital veins - Posterior auricular veins

Question 38

Describe the structures involved in the venous drainage of the scalp

Answer 38

- **Supraorbital** and **supratrochlear veins** unite at medial angle of eye to form angular vein (drains into the facial vein) - Deep parts of scalp in temporal region have veins which drain into the **pterygoid venous plexus**

Question 39

What is unique attribute of facial veins?

Answer 39

Veins of the face are valveless

Question 40

Describe the drainage of the facial vein

Answer 40

At medial angle of eye the facial vein communicates with superior ophthalmic vein and drains into the **cavernous sinus**

Question 41

Describe the clinical significance of the deep facial veins draining into pterygoid venous plexus

Answer 41

- Infection from facial vein can spread to dural venous sinuses - Infected clot can travel to intracranial venous system i.e. **thrombophlebitis of facial vein**

Question 42

What is the danger of the triangle of the face?

Answer 42

Infections in this region of the face can spread through the venous system to the dural venous sinuses

Question 43

The sigmoid sinus is a dural venous sinus. Describe its anatomical course

Answer 43

The **sigmoid sinuses** continue as the internal jugular veins, leaving the skull through the jugular foramina

Question 44

Why is the external jugular vein easier to see?

Answer 44

The internal jugular vein lies under sternocleidomastoid

Question 45

The internal jugular vein is a better indication of pressure in the right atrium. How is this measured?

Answer 45

- Right IJV used - Pulsations observed through muscle - Measured in cmH₂O - Height from sternal angle + 5cm

Question 46

Why might a doctor wish to listen over the carotid artery with a stethoscope?

Answer 46

- Check for degree of stenosis - Listening for **carotid bruit** (systolic sound indicating turbulent blood flow)

Question 47

Why is it helpful for a patient to hold his/her breath during auscultation of the carotid arteries?

Answer 47

Noise of breathing disrupts transmittent sounds

Question 48

Name the holes in the base of the skull through which the following vessels travel: - Internal carotid artery - Internal jugular vein - Middle meningeal artery - Vertebral artery

Answer 48

- **Internal carotid artery:** carotid canal **- Internal jugular vein:** jugular foramen - **Middle meningeal artery:** foramen spinosum - **Vertebral artery:** foramen magnum