Vasculature Flashcards
What are the arterial pathways of the neck?
-CCA (common corotid)
-ECA (external carotid)
-ICA (internal carotid)
-VA (vertebral artery)
What is the pathway of the external carotid artery to the external skull?
8 Branches (only have to know these 4)
-superior thyroid artery: branches from ECA and descends to the thyroid gland of the neck
-facial artery: branches from ECA and ascends across the mandible to supply the face and land in the orbit (eye socket)
-maxillary artery: branches from ECA and runs in the pterygopalatine fossa (space underneath the zygomatic arch) and ascends toward the orbit (eye socket)
-superficial temporal artery: “terminal branch of ECA”
which branches across the temporal fossa toward the orbit (eye socket)
***(in ascending order)
What is a clinical application of the ECA pathway to the external skull ?
The facial artery, maxillary artery, and superficial temporal arteries form a network/anastomosis around the eye socket where they land
***These arteries merge into the ophthalmic artery which branches off of the circle of willis
-The ECA pathway allows blood to enter the brain in this direction to compensate for any circumstance of occlusion of the blood supply to the brain (i.e. occlusion/stenosis of the ICA)
“mother nature’s way of compensating/creating a plan b”
What is giant cell arteritis (temporal arteritis)?
Inflammatory condition that results as a complication of polymyalgia rheumatica (PMR)
- usually patient complains of severe headache/pounding of temporal region (superior temporal artery inflamed)
What is the pathway of the internal carotid artery to the internal skull and brain?
Enters the skull through the carotid canal and makes a bend (turns horizontal) to travel through through the temporal bone
It then uses the foramen lacerum (cartilage floor) to turn vertical and ascend to/supply the circle of willis
What is the pathway of the vertebral artery to the internal skull and brain?
-Ascends from the neck through the transverse foramen of the spine
-Enters the skull through the foramen magnum
-Right and Left vertebral arteries then merge to form the basilar artery (a single artery)
-the basilar artery ascends in front of the brainstem and enters the circle of willis posteriorly
What does the circle of willis act as?
A rotary of blood supply to the skull, sends out 3 major branches (cerebral arteries) to the brain
What two arteries supply blood to the circle of willis?
ICA and basilar
What does the circle of willis consist of?
-ACA (anterior cerebral artery): heads out to the front (R/L)
-Anterior communicating arteries: connection between ICA and ACA, helps blood reach areas that could become occluded
-MCA (middle cerebral artery): heads out to the side (R/L), branches off of the R&L ICA in the circle of willis
-Posterior communicating arteries: connection between PCA and ICA, helps blood reach areas which could be occluded
-PCA (posterior cerebral artery): heads out to the back (R/L), basilar artery splits into two branches to form the R/L PCA
What is the pathway of the middle meningeal artery to the internal skull and brain?
-branches from the maxillary artery and enters the skull through the foramen spinosum
-branches out across/supplies the lateral skull and pterion region
rupture of this artery will cause an epidural hematoma
What are the major veins that drain the head and neck?
-brachiocephalic vein
-internal jugular vein
-external jugular vein
-vertebral vein
What is the overall pathway for venous return in the head/neck?
internal jugular veins, external jugular veins, and subclavian veins all merge into the brachiocephalic veins on both sides
- all land into the superior vena cava and the heart
How does the IJV drain circulation from the head/neck?
-IJV will drain the internal skull and some veins of the face
-descends down deep to SCM and merges with the subclavian to form the brachiocephalic vein
-Right and left brachiocephalic veins join to form the SVC (superior vena cava) and drain to the heart
***IJV exits the skull through the jugular foramen (jugular foramen also contains CN 9,10,11)
How does the EJV drain circulation from the head/neck?
-EJV will drain the veins of the external skull (face/scalp)
-descends down superficial to SCM and merges into brachiocephalic system to return the blood to the heart
