Session 3 Flashcards
Session 3 Head and neck
Describe the major blood vessels supplying and draining the head, neck and face and appreciate their general route and location. LO
- The arterial supply to the head and neck arises from branches of the?
right and left common carotid arteries and the vertebral arteries.
Q. 1. The vertebral arteries are branches of?
- Supply?
- General route?
A. subclavian arteries
- posterior neck and posterior parts of the brain (e.g. brainstem, cerebellum).
- -Artery ascends through the transverse foramina of the cervical vertebrae (except C7)
- Enters the subarachnoid space just between the atlas and occipital bone
- Passes up through the foramen magnum, curving around the medulla, to join the vertebral artery from the other side to form the basilar artery.
- The basilar artery runs along the anterior (ventral) aspect of the brainstem (namely the pons)
Q. Which common carotid artery is longer? Why?
A. - left common carotid artery
- The right common carotid artery originates from the brachiocephalic artery behind the right sternoclavicular joint, whilst the left common carotid arises directly from the arch of the aorta.

Q. Each common carotid artery ascends up through the neck enclosed within the ?
A. carotid sheath
Q. The carotid sheath is a fascial envelope enclosing the?
Most of the carotid sheath runs deep to the ? and is derived from fusion of ?
The sheath is ? over the vein but ? around the artery.
- State the position of the contents of the carotid sheath in relation to the sheath.
- where does the sympathetic trunk lie?
A. - carotid artery, internal jugular vein and vagus nerve
- sternocleidomastoid muscle
- a) the prevertebral layer of cervical fascia (posteriorly), b) the pretracheal layer (anteromedially) and c) the investing layer of cervical fascia (anterolaterally)
- thin, thicker
- The artery lies medially within the sheath whilst the vein is lateral and the nerve behind and in between the vessels.
- outside of the sheath, medially and behind it
Q. Which artery supplies intra cranial structures and which supplies extracranial structures? How do you know?
A. The internal carotid artery is distinguished by a lack of branches in the neck as it ascends to supply intra-cranial structures.
External carotid artery, is the major source of blood supply to extra-cranial structures of the head and neck region, and gives rise to eight branches.
Q. The external carotid artery divides into its terminal branches, the maxillary and superficial temporal arteries at which anatomical landmark?
A. At a level behind the neck of the mandible, within the substance of the parotid gland.
Q. Many of the branches of the external carotid artery make a loop at their origin; why do you think this is?






Q. Name the branches of the thyrocervical trunk and what they supply
A. • Ascending cervical & transverse cervical supply the neck
• Suprascapular supplies shoulder (posterior aspect of the scapula)
• Inferior thyroid supplies lower pole of the thyroid gland


Q. What are the borders of the carotid triangle and what makes up these borders?
A. Superior: Posterior belly of the digastric muscle.
Lateral: Medial border of the sternocleidomastoid muscle.
Inferior: Superior belly of the omohyoid muscle.

Q. What is the clinical significance of bifurcation of common carotid artery?
A. • Bifurcation of the carotid artery is a common site for atheroma formation
• Causes narrowing (stenosis) of the artery
• Rupture of the clot can cause an embolus to travel to brain
– TIA or stroke
Q. What is the Carotid sinus? Function?
What is the carotid body? Function?
A. Carotid sinus:
– swelling at region of bifurcation
– Location of baroreceptors for detecting changes in arterial BP detect arterial O2 (stretching opens channels results in action potentials)
Carotid body:
– Peripheral chemoreceptors which detect arterial O2

Q. What is the clinical significance of the carotid triangle? (4)
A. • Important for surgical approach to the carotid arteries or internal jugular vein (i.e. removal of a plaque)
• Can also access vagus and hypoglossal nerves via carotid triangle
• Carotid pulse can be felt in carotid triangle just below bifurcation
– may also be palpated more inferiorly (only do it one at a time)
• Carotid sinus massage (Reverse supra ventricular tachycardia due to increased vagus input to the heart. Sensitive can cause syncope)


Q. What is the cavernous sinus? What else does the cavernous sinus contain?
A. Plexus of extremely thin-walled veins on upper surface of sphenoid
– Internal carotid a
– CNIII oculomotor
– CNIV trochlear
– CNVI abducent
– 2 branches of trigeminal
• CNV1 ophthalmic and CNV2 maxillary
Q. What happens if an infection traces into the cavernous sinus?
A. Infections tracing into region - several structures it can impact on

Q. This image shows radio opaque dye within the internal carotid arteries what can you tell about the structure of these arteries?

Arteries have a tortuous structure
Q. The ophthalmic artery (OA) is the first branch of the ? distal to the cavernous sinus. Branches of the OA supply all the structures in the orbit as well as some structures in the nose, face and meninges. Occlusion of the OA or its branches can produce sight-threatening conditions.
A. internal carotid artery








































































