Major Blood Vessels Of Head And Neck

Question 1

What is a Carotid Endarterectomy?

Answer 1

Making an incision into the neck and carotid artery to remove plaque

Question 2

Is the IJV or EJV larger?

Answer 2

IJV

Question 3

Which 2 arteries to the head and neck branch off of the Subclavian Artery?

Which of these keep moving upwards to the skull?
Which one branches? What does it branch into?

Answer 3

• Vertebral Artery keeps moving upwards (through Transverse Foramina above C7)
• Thyrocervical Trunk-> Inferior Thyroid Artery

Question 4

What nerve does the Inferior Thyroid Artery come close to, that surgeons need to be careful of when operating on thyroid?

Answer 4

Recurrent Laryngeal Nerve (branch of Vagus)

Question 5

Why is the left common carotid artery slightly longer?

Answer 5

Left (arises directly from arch of aorta) travels for an extra 2cm in superior mediastinum before entering neck

Whereas right CCA branches off of subclavian artery

Question 6

Describe the organisation of the Carotid Sheath’s vessels

Where does the sympathetic chain lie in relation to the sheath?

Answer 6

CCA lies medially to vein, while vagus nerve is behind and in between the vessels

Sympathetic chain lies outside of the sheath, medially and behind it

Question 7

At the bifurcation of the CCA, why is the Internal Carotid Artery more bulbous?

Answer 7

Due to the Carotid Sinus (and Carotid body)

Sinus is just before the bifurcation

Question 8

What is the Carotid Sinus?

What is the Carotid Body?

Answer 8

A swelling of the CCA just before it bifurcates, containing Baroreceptors

A group of chemoreceptors that detect arterial O2

Question 9

Clinically, why can rubbing the carotid sinus firmly be beneficial?

Answer 9

A carotid massage can alleviate Supra-Ventricular Tachycardias

Question 10

Which parts of the head are supplied by the Vertebral arteries?

Answer 10

Posterior neck and posterior parts of brain (e.g Brainstem, Cerebellum)

Question 11

Describe the pathway of the Internal Carotid Artery up to the point where it branches to supply the brain and eye?

Explain in 4 steps

Answer 11

1. Ascends through neck, giving off no branches
2. Enters base of skull through Carotid Canal (In petrous part of temporal bone)
3. Turns Medially and Horizontally, then makes an S shaped bend
4. Passes through the Cavernous Sinus
5. Once it exits, it gives off its branches

Question 12

Briefly, what is the Cavernous Sinus?

Answer 12

A plexus of very thin-walled veins on the upper surface of the Sphenoid bone

Question 13

The Supra trochlear and Supra orbital arteries are facial arteries, but strangely they do not come from the External Carotid Artery.

Outline their branching pathway

Answer 13

Internal Carotid-> Opthalmic-> Supra Trochlear and Orbital arteries

Question 14

Which branch of the Internal Carotid Artery goes into the Optic nerve?

Why is it a very important artery?

Answer 14

Central Retinal Artery

If blood supply is lost, vision in that eye is lost (Can happen from embolism)

Question 15

Which areas do the Supra trochlear and Supra orbital artery supply?

Answer 15

Scalp (also supplied by external carotid artery)

Question 16

The 1st branch of the Internal Carotid is the Ophthalmic.

Name the 3 that form the anterior circulation of Circle of Willis and supply the brain

Answer 16

• Anterior cerebral artery
• Middle cerebral artery
• Posterior communicating artery

Question 17

What Arteries form the posterior circulation of the Circle of Willis?

What connects them to the Anterior circulation

Answer 17

Posterior cerebral artery, (branch from Basilar artery)

Connected to ant. circulation via Posterior Communicating artery

Question 18

How do the Vertebral Arteries travel up to the skull after branching off Subclavian artery?

Answer 18

1. Ascend through Cervical Transverse Foramina (except C7)
2. Enters sub-arachnoid space between Atlas and Occipital bone
3. Passes up through Foramen Magnum, curves around Medulla to join vertebral artery from other side-> Basilar artery

(This runs along anterior aspect of brainstem, namely the Pons)

Question 19

List the 8 External Carotid Artery Branches

“Some Anatomists Like Freaking Out Poor Medical Students)

Answer 19

1. Superior Thyroid
2. Ascending Pharyngeal
3. Lingual (oral cavity and tongue)
4. Facial
5. Occipital
6. Posterior Auricular
7. Maxillary
8. Superficial Temporal

Question 20

What are the 2 Terminal branches of the External Carotid?

Where can the facial pulse be felt?

Answer 20

Superficial Temoral and Maxillary (travel through Parotid gland, like facial nerve does)

Inferior border of mandible, anterior to Masseter muscle

Question 21

How do patients with Giant Cell Arthritis (GCA)/ Temporal arteritis present?

(Inflammation of superficial temporal artery)

Answer 21

• Frequent severe headaches
• Scalp tenderness/ pain (e.g brushing hair)
• Jaw pain while eating/ talking
• Loss of vision/ visual changes (can be permanent if not treated)

Question 22

As well as the parotid gland, the maxillary artery supplies deep tissue and bone structures (Nasal cavity + paransalsinuses)

It gives off a branch called the Middle Meningeal Artery (MMA) which runs through skull base.

What does it supply?

Answer 22

Meninges and skull bones

Question 23

Name the layers of the scalp

Which layer are the arteries in?

Answer 23

Skin
Connective tissue (arteries in here)
Aponeurosis 
Loose Areolar Tissue 
Periosteum

Question 24

Why can small scalp cuts lead to large amounts of bleeding?

Give 3 reasons

Answer 24

• Lots of anastomoses
• Artery walls held/ pulled open by connective tissue so can’t constrict
• Lacerations deep enough to cut aponeurosis-> Muscles of Occipitofrontalis ”pull” cut open more

Question 25

What opening does the Middle Meningeal Artery enter the skull from? Describe its branching

Answer 25

Enters through Foramen Spinosum, branch’s into Anterior and Posterior branches (Leaves an indent on skull in young age as it pushes on the bone)

Question 26

What is unique to facial veins?

Answer 26

Valveless

Question 27

Describe the drainage of the Superfical Temporal, Occipital and Posterior Auricular Veins into the Sublcavian vein

Answer 27

- Superficial Temporal and Occipital Combine together to form Retromandibular Vein - Posterior Auricular vein joins RM vein-> EJV - EJV-> Subclavian Vein

Question 28

Why can facial infection spread to intracranial structures?

Answer 28

Facial artery is connected to Superior and Inferior Opthalmic veins, which are directly connected to Cavernous Sinus AND Pterygoid Venous Plexus

Question 29

Why can scalp infections spread to intracranial structures?

Answer 29

Extra-cranial scalp veins are connected to Dural/ Intra-cranial Venous Sinuses, via Emissary veins running through the skull

Question 30

What is the Danger Triangle of the face?

Answer 30

Region where facial vein can drain backwards into Cavernous Sinus (Rare but dangerous) (Infections can end up in Dural Venous Sinuses_

Question 31

Describe the route of blood flow with regard to venous sinuses

Answer 31

- Cerebral veins drain into Superior Saggital Sinus - SS Sinus splits into left and right Transverse Sinuses - T Sinuses continue as Sigmoid Sinuses which bend in an S shape and drain into IVJ, exiting skull through Jugular Foramen

Question 32

As well as the facial vein, the IJV gets blood from the Tongue and Thyroid Gland. Describe its path into the SVC

Answer 32

Joins with Subclavian Vein to form Braciocephalic Vein, which drains into SVC

Question 33

Describe the drainage of the Supra Orbital and Trochlear veins into the facial vein

Answer 33

- Drain into Angular vein at Medial angle of eye towards inferior border of mandible. - Angular vein continues as facial vein (with facial artery) - Facial vein joins IJV (a continuation of the Sigmoid Sinus)

Question 34

What is Amaurosis Fugax

Answer 34

Visual loss due to a clot

Question 35

Other than the MMA, name an important branch of the Maxillary Artery

Answer 35

Sphenopalatine artery