Arterial Supply of Head and Neck

Question 1

What does the arterial supply of the head and neck arise from?

Answer 1

Branches of the right and left common carotid arteries and vertebral arteries

Question 2

What arises from the brachiocephalic trunk on the right?

Answer 2

• Subclavian
• Common carotid

Question 3

What do the subclavian arteries give rise to?

Answer 3

• Internal thoracic
• Thyrocervical trunk
• Vertebral arteries

Question 4

Where does the internal thoracic artery go?

Answer 4

Inside the ribcage

Question 5

What is the internal thoracic artery commonly used in?

Answer 5

Coronary artery bypass

Question 6

What does the thyrocervical trunk give rise to?

Answer 6

• Ascending cervical and transverse cervical
• Suprascapular
• Inferior thyroid

Question 7

What does the ascending cervical and transverse cervical supply?

Answer 7

The neck

Question 8

What does the suprascapular artery supply?

Answer 8

The shoulder

Question 9

What does the inferior thyroid supply?

Answer 9

The lower pole of the thyroid gland

Question 10

What do the vertebral arteries supply?

Answer 10

The posterior neck and posterior parts of the brain

Question 11

What course does the vertebral artery take from its origin?

Answer 11

It descends through the transverse foramina of the cervical vertebrae (except C7) and enters the subarachnoid space just between the atlas and occipital bone. It then passes jup through the foramen magnum, curving aroudn the medulla, to join the vertebral artery from the other side

Question 12

What does the vertebral artery eventually form?

Answer 12

The basilar artery

Question 13

Where does the basilar artery run?

Answer 13

Along the anterior aspect of the brainstem

Question 14

What branches does the common carotid give off in the neck?

Answer 14

None

Question 15

What does the right common carotid artery originate from?

Answer 15

The brachiocephalic artery

Question 16

Where does the right common carotid artery branch from the brachiocephalic artery?

Answer 16

Behind the right sternoclavicular joint

Question 17

Where does the left common carotid artery arise from?

Answer 17

The arch of the aorta

Question 18

What is the result of the differing origins of the right and left common carotid arteries?

Answer 18

The elft common carotid is slightly longer

Question 19

Where does the left common carotid course before entering the neck?

Answer 19

In the mediastinum, for about 2cm

Question 20

What is each common carotid artery enclosed within?

Answer 20

A carotid sheath

Question 21

What is the carotid sheath?

Answer 21

A fascial envelope enclosing and seperating several structures a

Question 22

What structures lie in the carotid sheath?

Answer 22

• Carotid artery
• Internal jugular vein
• Vagus nerve
• Deep cervical lymph nodes

Question 23

How does the sheath differ over the carotid artery compared to other areas?

Answer 23

It is thicker

Question 24

How does the carotid artery lie in the carotid sheath relative to other structures?

Answer 24

Lies medially within the sheath

Question 25

How does the sheath over the internal jugular vein differ in comparison to other areas?

Answer 25

It is thinner

Question 26

Where does the internal jugular vein lie in the carotid sheath relative to other structures?

Answer 26

Behind and inbetween vessels

Question 27

Where is the carotid sheath found, relative to muscles in the area?

Answer 27

Deep to the sternocleidomastoid muscle

Question 28

What is the carotid sheath derived from?

Answer 28

* The prevertebral layer of cervical fascia posteriorly * The pretracheal layer anteromedially * The investing layer anterolaterally

Question 29

Where does the sympathetic trunk lie relative to the carotid sheath?

Answer 29

Outside the sheath, medially and behind it

Question 30

Where do the common carotids terminate?

Answer 30

At the upper border of the thyroid cartilage

Question 31

How do the common carotid arteries terminate?

Answer 31

They divide into the internal and external carotid arteries

Question 32

What happens to internal carotid at the divison?

Answer 32

It is more bulbous

Question 33

Why is the internal carotid more bulbous at the division of the common carotids?

Answer 33

Because of the carotid sinus and the carotid body

Question 34

What is the carotid sinus?

Answer 34

A swelling at the region of bifurcation

Question 35

What is the function of the carotid sinus?

Answer 35

Location of baroreceptors for detecting changes in arterial BP

Question 36

What is the clinical relevance of the carotoid sinus?

Answer 36

Rubbing this area firmly, *termed a **carotid massage**, can alleviate supra-ventricular tachycardias*

Question 37

What is the function of the carotid body?

Answer 37

It's where the peripheral chemoreceptors are

Question 38

What do peripheral chemoreceptors do?

Answer 38

Detect arterial oxygen

Question 39

Briefly describe the blood and nerve supply of the carotid body

Answer 39

Very rich

Question 40

How is the internal carotid artery distinguished from the external?

Answer 40

By a lack of branches in the neck *as it ascends to supply intra-cranial structures*

Question 41

How does the internal carotid artery enter the skull?

Answer 41

Through the carotid canal

Question 42

What is the external carotid artery the major source of?

Answer 42

Blood supply to extra-cranial structures of the head and neck region

Question 43

What are the branches of the external carotid artery?

Answer 43

* Superficial thyroid * Lingual * Facial * Ascending pharyngeal * Occipital * Posterior auricular * Maxillary * Superficial temporal

Question 44

What are the terminal branches of the external carotid artery?

Answer 44

Maxillary and superficial temporal

Question 45

Where does the external carotid artery divide into its terminal branches?

Answer 45

At a level behind the neck of the mandible, within the substance of the parotid gland

Question 46

What does the maxillary artery notably give rise to?

Answer 46

The middle meningeal artery

Question 47

What do many of the branches of the external carotid artery do?

Answer 47

Make a loop at their origin

Question 48

What is the clinical relevance of the bifurcation of the carotid artery?

Answer 48

It is a common site for atheroma formation

Question 49

Why is the bifurcation of the carotid artery a common site for atheroma formation?

Answer 49

Because where blood meets the bifurcation, there is turbulence, leading to increased risk of atheroma formation

Question 50

What does atheroma formation at the bifurcation of the common carotid lead to?

Answer 50

Narrowing (stenosis) of the artery, limiting blood to the brain

Question 51

What can a rupture of the atheroma at the bifucation of the carotid artery cause?

Answer 51

An embolus to travel to the brain and get lodged in an artery there, leading to TIA or stroke

Question 52

What do most of the superficial arteries of the face arise from?

Answer 52

Common carotid

Question 53

What are the superficial arteries of the face?

Answer 53

* Supra-orbital * Supra-trochlear * Transverse facial * Angular * Lateral nasal * Maxillary * Superior and inferior labial * Facial

Question 54

What superficial arteries of the face do **not** arise from the common carotid?

Answer 54

Supra-orbital and supra-trochlear

Question 55

Where do the supra-orbital and supra-trochlear arteries arise from?

Answer 55

The opthalmic, *which is a branch of the internal carotid*

Question 56

What are the vessels that supply blood to the scalp largely branches of?

Answer 56

The external carotid artery

Question 57

What vessels supply blood to the scalp?

Answer 57

* Supra-orbital * Supratroclear * Superficial temporal * Posterior auricular * Occipital

Question 58

What is the result of the scalp being supplied by a rich blood supply of anastomoses?

Answer 58

Can get profuse bleeding

Question 59

Where do the vessels of the scalp lie?

Answer 59

In the subcutaneous connective tissue layer

Question 60

What are the walls of the arteries supplying the scalp attached closely to?

Answer 60

Connective tissue

Question 61

What is the result of the walls of the arteries of the scalp being closely attached to connective tissue?

Answer 61

Limits constriction, so can get profuse bleeding

Question 62

Why can deep lacerations to the epicranial aponeurosis cause profuse bleeding?

Answer 62

Due to the opposing pull of the occipitofrontalis muscle

Question 63

Does loss of scalp blood supply lead to bone necrosis?

Answer 63

No

Question 64

Why does loss of scalp blood supply not lead to bone necrosis?

Answer 64

Because blood supply to the scalp is largely from the middle meningeal artery

Question 65

What is the middle meningeal artery a branch of?

Answer 65

The maxillary artery

Question 66

What does the middle meningeal artery supply?

Answer 66

Skull and dura

Question 67

What is formed by the middle meningeal artery on the inside of the calvaria?

Answer 67

Grooves

Question 68

What are the branches of the middle meningeal artery?

Answer 68

Anterior and posterior

Question 69

Where does the anterior branch of the middle meningeal artery run?

Answer 69

Under the pterion

Question 70

What is the pterion?

Answer 70

A relatively thin area where a number of bones meet

Question 71

When is the pterion prone to damage?

Answer 71

When there is a blow to the side of the skull

Question 72

What can a fracture of the skull at the pterion cause?

Answer 72

Rupture of the middle meningel artery

Question 73

What happens when the middle meningeal artery is ruptured?

Answer 73

Bleeding occurs, causing an extradural haemorrhage. Blood builds up and rips the periosteal layer of dura away from bone, and blood compresses the brain

Question 74

What is the function of a craniotomy?

Answer 74

To gain access to the cranial cavity

Question 75

What happens in a craniotomy?

Answer 75

The bone and scalp flap is reflected inferiorly to preserve blood supply

Question 76

Why is the bone and scalp flap reflected inferiorly in a craniotomy?

Answer 76

Because that's how the arterial supply runs

Question 77

What is the purpose of preserving the arterial supply to scalp and bone in a craniotomy?

Answer 77

So they can be replaced