Week 2 - Blood Vessels of the H+N

Question 1

What is the fate of the common carotid in the neck -

Does it have any branches?

Answer 1

No branches

Bifurcates into internal and external carotids

Question 2

At what level does the common carotid artery bifurcate?

Answer 2

Level of the superior border of the thyroid cartilage (C4)

Question 3

What is the carotid sinus?

What is its purpose?

Answer 3

Swelling of the ICA in the region of the bifurcation of the common carotid.
Contains baroreceptors

Question 4

Which nerve carries signals from the baroreceptors?

Answer 4

Glossopharyngeal nerve

Question 5

What is the carotid body?

What is its function?

Answer 5

Cluster of nerve cells sitting at bifurcation of common carotid.
Contains peripheral chemoreceptors

Question 6

Why might a young man experience syncope whenever he wears a tie?

Answer 6

Hypersensitive baroreceptors - external pressure on neck stimulates them. Pushes HR and BP down –> syncope.

Question 7

Does the ICA have any branches in the neck?

Answer 7

NO!

Question 8

Through what hole does the ICA enter the skull?

Answer 8

Carotid canal

Question 9

What is the most important branch of the ICA?

Which superficial arteries does this give rise to?

Answer 9

Ophthalmic artery –>

• Supraorbital artery
• Supratrochlear artery

Question 10

Name the 6 branches of the ECA in the H+N

Answer 10

• Superior thyroid artery
• Ascending pharyngeal artery
• Lingual artery
• Facial artery
• Occipital artery
• Posterior auricular artery

Question 11

How and where does the ECA terminate?

Answer 11

In the parotid, terminates by dividing into:

• Maxillary artery
• Superficial temporal artery

Question 12

What are the 4 important branches of the facial artery?

Answer 12

• Angular artery
• Superior and inferior labial arteries
• Lateral nasal artery

Question 13

List the layers of the scalp from superficial to deep

Answer 13

Skin
CT
Aponeurosis (epicranial)
Loose CT
Periosteum

Question 14

In which layer of the scalp would you find the blood vessels?

Answer 14

The CT layer

Question 15

Which 5 arteries supply the scalp?

For each, does it arise from the ICA or ECA?

Answer 15

• Supraorbital - from ICA
• Supratrochlear - from ICA
• Superficial temporal - from ECA
• Posterior auricular - from ECA
• Occipital - from ECA

Question 16

Give 3 reasons why scalp injuries bleed profusely

Answer 16

1) Densely vascular as numerous anastomoses
2) Walls of arteries bound to underlying CT which holds their lumens open
3) If the laceration is deep enough the involves the epicranial aponeurosis, the pull of occipitofrontalis also holds the vessels open

Question 17

Why is the middle meningeal artery clinically relevant?

From which vessel does it arise?

Answer 17

Anterior middle meningeal artery lies immediately under the pterion - prone to fracture. Rupture of the artery leads to extradural haemorrhage.
Arises from the maxillary artery

Question 18

What are the 3 branches of the subclavian artery?

Answer 18

• Vertebral artery
• Internal thoracic artery
• Thyrocervical artery

Question 19

What structures drain the:

• Brain and meninges
• Scalp and face
• Neck

Answer 19

• Dural venous sinuses
• Veins synonymous with the arteries
• Anterior jugular veins

Question 20

Describe the relative sizes and positions of the jugular veins

Answer 20

• EJV - smaller and superficial to muscles

- IJV - larger, deep to SCM - can be accessed in carotid triangle

Question 21

How would you measure JVP?

What is an abnormally high JVP?

Answer 21

• Patient at 45*
• Look for pulsations between the 2 heads of SCM
• Measure the height above the sternal angle + 5cm, as RA is 5cm below the angle
• > 9cm = high

Question 22

Which 2 veins unite to form the EJV?

Where?

Answer 22

Posterior auricular vein and retromandibular vein

Join immediately posterior to the angle of the mandible

Question 23

Give 2 reasons why pressure must be applied to a severed EJV?

Answer 23

• Stop bleeding

- Prevent air entry

Question 24

Where does the IVJ begin?

Answer 24

In the cranial cavity, as a continuation of the sigmoid sinus

Question 25

Through which hole does the IJV leave the skull?

Answer 25

Jugular foramen

Question 26

Regarding venous drainage of the scalp and face, how do the veins relate to the arteries?

Answer 26

• Arteries from ECA have synonymous veins which follow the same course.
• Arteries from the ICA have synonymous veins but they DO NOT follow the same course

Question 27

Describe the course of the Supraorbital and Supratrochlear veins

Answer 27

• Unite at medial angle of eye
• Form angular vein
• Drains into facial vein

Question 28

What are the Dural sinuses?

Answer 28

• Endothelium-lined spaces between the periosteal and meningeal layers of dura mater –> meningeal layer folds in at Dural septae
• Collect venous blood from the veins draining the brain and skull

Question 29

How might infection spread from the scalp to the brain?

Answer 29

Via the emissary veins which connect the veins of the scalp to the Dural sinuses

Question 30

What is thrombophlebitis?

How can it spread from the face to the brain?

Answer 30

Infected blood clot

Flows backwards from the facial vein to the cavernous sinuses as there are no valves.

Question 31

Which nerves are found within the cavernous sinus?

Anything else?

Answer 31

• III
• IV
• V - ophthalmic and maxillary branches only
• VI
• the ICA

Question 32

Which vessels arise from the arch of the aorta?

Answer 32

Left - Subclavian and common carotid

Right - brachiocephalic trunk –> gives off subclavian and common carotid