Major Blood Vessels of Head and Neck

Question 1

Explain the main branches off the aortic arch

Answer 1

• Arch of the aorta splits into Brachiocephalic trunk on the left
• Brachiocephalic splits into right subclavian and right common carotid
• Left common carotid branches directly off the aorta
• Left subclavian direct branch off the aorta

Question 2

Which arteries of the neck arise off the the right subclavian?

Answer 2

Vertebral, internal thoracic and thyrocervical arteries

Question 3

What are the 2 branches of the left common carotid artery?

Answer 3

Internal and External

Question 4

At what level does the common carotid artery bifurcate?

Answer 4

At the superior border of the thyroid cartilage

(around C4 in the carotid triangle)

Question 5

From where do the vertebral arteries arise?

Answer 5

From the left and right subclavian arteries

Question 6

Describe the route of the vertebral arteries from the subclavian arteries

Answer 6

• Ascend from subclavian arteries through the transverse foramina of cervical vertebrae C6 → C1
• Pass through the foramen magnum into the skull and join together froming the Basilar artery

Question 7

What do the vertebral arteries supply?

Answer 7

The brain

(along with the internal carotid arteries)

Question 8

How does the internal carotid artery enter the skill?

Answer 8

Through the carotid canal in the temporal bone

Question 9

What is clinically significant about the bifurcation of the carotid artery?

Answer 9

A common site for atheroma formation

• Causes stenosis of the artery
• Clot rupture can travel to brain causing TIA/ Stroke

Question 10

What is the carotid sinus?

Answer 10

Swelling at the site of carotid artery bifurcation where baroreceptors are located

Question 11

What is the carotid body?

Answer 11

Area at carotid artery bifurcation with rich blood supply with peripheral chemoreceptors which detect arterial O₂

Question 12

Which nerves can be accessed via the carotid triangle?

Answer 12

Vagus and hypoglossal

Question 13

When would carotid sinus massage be used? How does it work?

Answer 13

In supraventricular tachycardia

Massage increases blood pressure detected by baroreceptors activating parasympathetic NS

Question 14

Describe the route of the internal carotid artery

Answer 14

• Enters the skull through carotid canal in temporal bone
• Turns medially and horizontally
• Enters cranial cavity and makes S shaped bend through to cavernous sinus

Question 15

What structures does the internal carotid artery supply?

Answer 15

1. Brain
2. Eyes
3. Forehead

Question 16

What structures are contained within the cavernous sinus?

Answer 16

• internal carotid artery
• Cranial Nerve 3 (occulomotor)
• Cranial Nerve 4 (trochlear)
• Cranial Nerve 6 (abducent)
• 2 branches of trigeminal nerve

Question 17

Where does the Opthalmic artery branch from?

Answer 17

Internal Carotid Artery

Question 18

Name the branches of the opthalmic nerve

Answer 18

• Ethmoidal arteries
• Supratrochlear artery
• Supra-orbital artery

Question 19

Name the Branches of the External Carotid Artery (there are 8!)

Answer 19

1. Superior Thyroid
2. Ascending Pharangeal
3. Lingual
4. Facial
5. Occpital
6. Posterior auricular
7. Maxillary
8. Superficial Temporal

Question 20

Which branches of the external carotid artery are considered terminal?

Answer 20

Maxillary and Superficial Temporal

Question 21

What are the layers of the Scalp?

Answer 21

Question 22

Describe the blood supply to the scalp

Answer 22

Question 23

What is the significant of many anastamoses between extra cranial and intracranial veins of the scalp?

Answer 23

Provide a potential route for infection to spread across the cranial cavity

Question 24

Give the reasons why cuts to the scalp often bleed profusely

Answer 24

1. Numerous anastomoses
2. artery walls closely attached to connective tissue limits artery constriction
3. Lacerations of epicranial aponeurosis are pulled open by occipitofrontalis

Question 25

Where do the superficial arteries of the face all arise from?

Answer 25

All from **external carotid** except supra-orbital and supratrochlear (from internal carotid)

Question 26

Where can the facial artery be felt?

Answer 26

At the inferior border of the mandible, anterior to masseter muscle

Question 27

Where does the nasal septum get its blood supply from?

Answer 27

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

Question 28

What is **Kiesselbach's area** and what is it's clinical signifcance?

Answer 28

Are of anastamoses of arteries in nasal septum Common site for nose bleeds (epistaxis)

Question 29

Which arteries supply the dura and the skull?

Answer 29

Posterior and anterior branches of **middle meningeal artery**

Question 30

What is the clinical significance of the **Pterion** of the skull?

Answer 30

Pterion is the weakest point of the skull The **Middle Memingeal artery** runs under pterion so fracture of the skull at this point can lacerate the MMA Blood accumulation between dura matter and skull causes **extradural haemorrhage**

Question 31

Describe the venous drainage of the head and neck

Answer 31

* **Venous drainage of the brain and meninges**: Supplied by the *dural venous sinuses*. * **Venous drainage of the scalp and face:** Drained by veins *synonymous* with the arteries of the face and scalp. These empty into the *internal and external jugular veins.* * **Venous drainage of the neck**: Carried out by the *anterior jugular veins.*

Question 32

How does venous drainage of the scalp connect to diploic veins of the skull and what is the clinical signifcance of this?

Answer 32

Via **emissary veins** which are **valveless** Infection from scalp can spread to cranial cavity and affect the meninges

Question 33

Where do facial veins drain into?

Answer 33

The **pterygoid venous plexus**

Question 34

What is the clinical significance of facial veins draining to pterygoid venous plexus?

Answer 34

* infection from facial vein can spread to dural venous sinuses * thrombophlebitis of facial vein- infected clot can travel to intracranial venous system

Question 35

What is the danger triangle?

Answer 35

Area of the face with extensive communication between extra and intra cranial veins Infections from face can track intra-cranially resulting in serious infection

Question 36

What is the sigmoid sinus?

Answer 36

Continuation of the dural venous sinus that becomes the **internal jugular vein**

Question 37

Describe the route of the IJV

Answer 37

Runs legnth of neck in the carotid sheath in a straight line from **lobule of ear** to **sternoclavicular joint** Mainly covered by SCM

Question 38

Where can central lines be inserted into the IJV?

Answer 38

At the point SCM splits into clavicular and sternal heads