Session 1.3a - Pre-Reading (Arterial Supply of the Head and Neck) Flashcards
https://www.youtube.com/watch?v=Un1ZWP_BdCk
How many common carotid arteries (CCA) are there?
2 - one on the right, and one of the left
Where does the CCA arise from?
The arch of aorta
Where does the left CCA arise from?
Directly from the arch of aorta before running up the length of the neck.
Where does the right CCA arise from?
The brachiocephalic trunk (sometimes known as the brachiocephalic artery), which is essentially the first branch off the arch of aorta.
How does the brachiocephalic trunk terminate?
It divides into the right subclavian artery and the right common carotid artery
What does the subclavian artery supply?
The upper limb
Where does the right CCA ascend up the neck?
It runs up the length of the neck on the opposite side to where the L CCA is positioned.
The CCAs ascend up the neck within which structure?
The carotid sheath
The level of C4 is approximately where …?
- The upper margin of the thyroid cartilage lies
- The CCAs terminate into their two terminal branches
At approximately which cervical level is the upper margin of the thyroid cartilage?
C4
At approximately which cervical level do the CCAs terminate into their two terminal branches?
C4
Which side and what view of the head and neck are we looking at in image A?
The right side from a lateral view.
Which side of the body can the brachiocephalic trunk/artery be found?
Right
At about the 4th cervical vertebra the CCA terminates. What does it continue as?
The external and internal carotid artery (ECA and ICA).
Where does the vertebral artery arise from?
The subclavian artery
What is the route of the vertebral artery?
- Initially runs in front of C7
- As the artery ascends up the neck, it enters a bony channel created by the transverse foramina of the cervical vertebra
- Then runs intracranially through the foramen magnum
- Finally joins an anastomosis of other arterial blood vessels, creating ultimately the Circle of Willis.
(C7, transverse foramina, foramen magnum, Circle of Willis)
Where does the thyrocervical trunk arise from?
The subclavian artery
How many branches does the thyrocervical trunk give off?
4
Where does the inferior thyroid artery arise from?
The thyrocervical trunk (from the subclavian artery)
What sort of structure does the inferior thyroid artery have? (Think about its shape)
It runs a torturous course
Where does the inferior thyroid artery terminate?
The inferior part of the thyroid gland.
What does the inferior thyroid artery supply?
Arterial blood to the thyroid gland
Which nerve is closely associated with the inferior thyroid artery?
The recurrent laryngeal nerve
The recurrent laryngeal nerve is a branch of which nerve?
The vagus nerve/cranial nerve X
What does the recurrent laryngeal nerve supply?
Motor and sensory innervation to structures of the larynx.
Surgeons sometimes need to perform operations relating to the thyroid gland to stem bleeding during the operation. This may involve the need to ligate the inferior thyroid artery to prevent bleeding. What complications may arise from this?
There may also be damage to the recurrent laryngeal nerve, as it is closely associated with the inferior thyroid artery. It is therefore very important that surgeons take great care over the nerve during surgical operations.
Name the branches of the subclavian artery.
- Vertebral artery
- Inferior thyroid artery
- Costocervical trunk
- Internal thoracic (or internal mammary) artery
The external carotid artery and its branches form the main arterial supply to the …
Scalp, face and neck.
What is the main arterial supply to the scalp, face and neck?
The branches of the external carotid artery
What do the branches of the ICA on the neck supply?
Trick question - The ICA arises from the bifurcation of the CCA and ascends through the neck without giving any branches at all.
Where does the internal carotid artery enter the skull?
Through the base of the skull in the carotid canal
Where does the ICA branch?
Within the intracranial cavity
How many branches does the ECA have?
8
Image 2
Which aspect of the head and neck are we visualising here?
The left aspect
Name a mnemonic to remember the branches of the external carotid artery.
Some Anatomists Like Freaking Out Poor Medical Students.
What is the first branch of the external carotid artery?
The superior thyroid artery.
Which artery do we see arising almost immediately after the CCA bifurcates?
The superior thyroid artery.
What does the superior thyroid artery supply?
Important for bringing arterial blood to the thyroid gland.
What is the second branch of the ECA?
Ascending pharyngeal artery
What is the structure of the ascending pharyngeal artery?
It is a small branch that arises from the ECA, and heads superiorly.
What is the third branch of the ECA?
Lingual artery
Where does the lingual artery terminate?
The oral cavity and the tongue.
What is the main arterial supply to the structures of the face?
The facial artery
How can you palpate the pulse of the facial artery?
- Feel carefully on the inferior border of the mandible/jaw
- Find the superior margin of the masseter muscle (clench your jaw)
- Feel just in front of here, and you may be able to palpate the pulse of the facial artery as it curves around the mandible.
What is the fourth branch of the ECA?
The facial artery
What is the fifth branch of the ECA?
Occipital artery.
Where is the occipital artery found?
The posterior aspect of the skull
What does the occipital artery supply?
It forms part of the rich anastomosis of vessels supplying blood to the scalp.
What is the 6th branch of the ECA?
Posterior auricular artery
Where is the posterior auricular artery found?
Posteriorly behind the ear
auricular = ear
What does the posterior auricular artery supply?
The skin of the scalp.
What are the terminating branches of the ECA?
The maxillary artery and the superficial temporal artery (last two)
What are the last two branches of the ECA?
The maxillary artery and the superficial temporal artery (last two)
Where is the superficial temporal artery found?
It runs up over the area of the temple on the lateral aspect of the skull.
What are the 8 branches of the ECA?
- Superficial thyroid artery
- Ascending pharyngeal artery
- Lingual artery
- Facial artery
- Occipital artery
- Posterior auricular artery
- Maxillary artery
- Superficial temporal artery
Which branches of the ECA supply arterial blood to the scalp?
- Posterior auricular
- Occipital
- Superficial temporal
Which branches of the ICA supply arterial blood to the scalp?
- Supratrochlear
- Supraorbital
Where do the blood vessels of the scalp from the ICA arise from?
The intracranial branches that arise from the ICA will have ultimately arisen from the orbit to run up the front of the skull
Which layer of the scalp do the supratrochlear and supraorbital artery run in?
The dense connective tissue layer
What forms the blood supply of the scalp?
A rich anastomosis of blood vessels from:
Branches of the external carotid artery:
- Posterior auricular artery
- Occipital artery
- Superficial temporal artery
and
Branches of the internal carotid artery:
- Supratrochlear artery
- Supraorbital artery
Fig. 1
Identify the:
- Right common carotid artery
- Left common carotid artery
- Right subclavian artery
- Left subclavian artery
- Brachiocephalic trunk
- C4
See answers.
Note: the right CCA is a branch off the brachiocephalic trunk, whereas the left CCA comes directly off the arch of aorta.
C4 is the level of the CCA bifurcation.
Fig. 2
Identify the:
- Vertebral artery
- Inferior thyroid artery
- Costocervical trunk
- Internal thoracic
- Thyrocervical trunk
- C7
See answers.
Extra
Fig. 1
- Identify the arch of aorta
Fig. 2 Identify the: - Brachiocephalic trunk - Right subclavian artery - Right common carotid artery - C4 - External carotid artery - Internal carotid artery - Foramen magnum
See video (Fig. 2 answers) 01:45 - 02:20
Fig. 3
Label the figure
See answers
