Blood Supply Flashcards
Where do the vertebral arteries arise from?
The subclavian arteries
Where do the vertebral arteries go?
Ascend though the transverse foramina in cervical vertebrae 6-1
Where do the vertebral arteries supply?
The brain along with the internal carotid arteries
Where do the branches of the internal carotid arise from and where do they go?
Internal carotid does not give off branches in the neck
Enters skull through carotid canal
Forms the circle of Willis
Where does the common carotid bifurcate?
The level of the superior border of the thyroid cartilage
What is located in the carotid sinus?
Baroreceptors for detecting changes in arterial BP
What is in the carotid body?
Peripheral chemoreceptors for detection of arterial oxygen
What is the carotid sinus?
Swelling in the region of the bifurcation
Why is the bifurcation of the common carotid a common site for atheroma?
Get turbulent blood flow
Compilation of atheroma at the bifurcation of the common carotid?
Stenosis - limits blood flow to the brain
Rupture of a clot can cause an embolus to travel to the brain causing a TIA or stroke
What is the carotid sinus massage?
Be done to mimic an increase in blood pressure, activating baroreceptors and slowing heart rate
Six branches of the external carotid and the terminal branches?
Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior auricular
Terminal branches:
Maxillary
Superficial temporal
Stop Alcohol Late Friday Or Puke More Saturday
Branches of the internal carotid that supply the scalp?
Ophthalmic branches to give:
- Supra-orbital
- Supra-trochlea
Branches of the external carotid that supply the scalp?
Superficial temporal
Posterior auricular
Occipital
Why do head wounds often result in profuse bleeding?
Walls of arteries in the scalp are closely attached to connective tissue, limiting constriction
Numerous anastomoses
Deep lacerations involving epicranial aponeurosis causes profuse bleeding because of opposing pull of occipitofrontalis muscle
What is the main blood supply to the scalp?
Middle meningeal artery
What are the main superficial veins which drain the face?
Superficial temporal
Posterior auricular
Occipital
Which to veins join to form the angular vein and where? Where does the angular vein drain into?
Supraorbital and supratrochlea
Medial angle of the eye
Drains into facial vein
Where do some deep parts in the temporal region of the scalp drain into?
Pterygoid plexus
How can infection of the scalp spread to the cranial cavity and affect the meninges?
Veins of the scalp connect to the diploic veins of the skull via several valveless emissary veins and therefore connect to the rural venous sinuses.
What is the blood supply to the dura and the skull?
External carotid -> maxillary artery -> middle meningeal artery -> anterior and posterior branches
What type of haemorrhage do you get if the middle meningeal artery is ruptured at the pterion?
Extradural haemorrhage
What is a craniotomy and how is the blood supply preserved?
Allows access to the cranial cavity
Bone and scalp flap are reflected inferiorly
What are the dural venous sinuses?
Endothelium-lined spaces between the periosteal and meningeal layers of the dura mater. They form the dura septae.
Where does the sigmoid sinus go?
Continues as the internal jugular vein
Exits via the jugular foramen
Where does the dural venous sinus receive blood from?
The large veins that drain the brain
Name the dural venous sinuses
Sigmoid sinus Transverse sinus Superior saggital sinus Inferior saggital sinus Cavernous sinus
Name the superficial arteries of the face
External carotid:
- facial
- superior and inferior labial
- maxillary
- lateral nasal
- angular
- transverse facial
Internal carotid:
- supratrochlear
- supraorbital
Where do most of the veins of the face drain into?
Facial vein -> internal jugular vein
What is in the cavernous sinus?
Thin-walled veins Internal carotid artery Cranial nerves -occulomotor -trochlear -abducent -trigeminal - ophthalmic and maxillary
Where is the cavernous sinus?
On the upper surface of the sphenoid bone
What does the facial vein communicate with at the medial angle of the eye and where does it drain to?
Superior ophthalmic
Cavernous sinus
Where do the deep facial veins drain into?
Pterygoid venous plexus
How can infection get to the dural venous sinuses?
From facial vein, to pterygoid plexus to the dural venous sinuses
Where can thrombophlebitis of the facial vein travel to?
This is an infected clot.
To the intracranial venous system
What can be found in the cavernous sinus?
Internal carotid artery Oculomotor nerve Trochlear n. Abducens n. Trigeminal n. - V1 and V2
