Head and Neck: Major blood vessels Flashcards
What are the branches of the thyrocervical trunk?
What do they supply?
The asc cervical and transverse cervical arteries which supply the neck
The suprascapular artery which supplies the shoulder
The inferior thyroid artery which supplies the lower pole of the thyroid gland
Describe the course of the vertebral arteries
They arise from the subclavian arteries and asc up the neck through the transverse foramina
They supply the brain along with the internal carotid
Anastomose in the brain to form the circle of willis
At what level does the common carotid artery bifurcate at?
The superior border of the thyroid cartilage
What is the role of the carotid sinus?
The carotid sinus is a swelling at the bifurcation which has baroreceptors for detecting changes in arterial BP
What is the carotid massage?
A technique used to correct supraventricular tachycardia by imitating high BP so HR decreases
Massage the carotid triangle
What is the role of the carotid body?
Has peripheral chemoreceptors which detect arterial O2
Why is atheroma formation common at the site of the carotid artery bifurcation?
What is the consequence of this?
Often a turbulent site which make increase risk of atheroma formation
If unilateral will not affect brain and blood from the other side can compensate
Emboli can travel to the brain and cause a transient ischaemic attack or a stroke
What are the boundaries of the carotid triangle?
Anterior border of sternocleidomastoid
Superior belly of omohyoid
Posterior belly of digastric
What are the contents of the carotid triangle?
Internal jugular vein, bifurcation of the common carotid artery
What is the blood supply to the scalp?
Branches of external carotid: superficial temporal, posterior auricular and occipital
Branches of internal carotid (from opthalmic): supra orbital and supratrochlear
What is the venous drainage of the scalp?
Superficial veins which accompany the artieries: superficial temporal veins, occipital veins, posterior auricular veins
The supraorbital and supratrochlear veins unite at the medial angle of the eye to form the angular vein which drains into the facial vein
Some deep parts in the temporal region have veins draining into the pterygoid venous plexus
What are the emissary veins?
Veins of the scalp that connect to diploic veins of the skull
They are valveless so blood can go in either direction - therefore can spread infection to the meninges
What is the blood supply to the skull and dura?
The middle meningeal artery
What is an extradural haemorrhage?
Blood accumulates and rips the dura away from the skull
The increased pressure can compress the brain
What are the dural venous sinuses?
Endothelial lined spaces between the periosteal and meningeal layers of the dura
They receive blood from veins and some CSF and drain into the internal jugular vein
