Blood vessels of head and neck Flashcards
What is the blood supply to the head?
- internal carotid x2
- external carotid x2
- verteral arteries x2
Where do the internal carotid arteries supply?
- brain and eyes
Where do the external carotid arteries supply?
- extracranial structures (scalp, face)
Where do the vertebral arteries supply?
- brain
What is the origin of the internal and external carotid arteries?
- bification of the common carotid artery
What are the collateral branches of the aortic arch?
- brachiocephalic trunk
- left common carotid artery
- left subclavian artery
What does the brachiocephalic trunk terminally divide into?
- right common carotid artery
- right subclavian artery
At what point does the brachiocephalic trunk terminally divide?
- right sternoclavicular joint
What percentage of people have a normal aortic bification?
- 64.9%
What is the main aortic bificiation variation and what percent of population have this?
- left common carotid and left subclavian artery share common origin of the aortic arch
- 27.1%
Where do the subclavian arteries terminate?
- terminates at external margin of 1st rib
What do the subclavian arteries become continuous with?
- becomes continuous with axillary arteries (don’t end just change name)
What are the major collateral branches of the subclavian artery?
- vertebral (goes up)
- internal thoracic/mammaries (give rise to intercostal arteries)
What are the 4 main parts of the vertebral artery (include vertebral level)?
- cervical part (until C6)
- Vertebral part (C6-C1)
- Suboccipital part (C1 - foramen magnum)
- Intracranial part (once it crosses foramen magnum)
What is the course of the common carotid arteries?
- ascends posterolateral to trachea and larynx
Is there any collateral branches of the common carotid arteries?
- no
What s the termination of the common carotid arteries?
- terminally divides into external and internal carotid arteries at superior boarder of thyroid cartilage
- C3/4
What is the major differences between the internal and external carotid arteries?
- the internal carotid artery has a wider diameter and is located posterolateral to external carotid artery
What is the carotid sinus?
- is a dilation of the most proximal part of internal carotid artery
- contains baroreceptors (for pressure) in walls
What do the collateral branches of the external carotid arteries supply?
- thyroid gland
- all parts of head except brain and eyes
What are the terminal branches of the external carotid arteries?
- maxillary artery –> middle meningeal artery is a collateral branch of this
What is the origin of the middle meningeal arteries?
- collateral branch of maxillary artery of external carotid artery
What does the middle meningeal artery supply?
- cranial bone and dura
Where does the middle meningeal artery enter the cranial cavity?
- through the foramen spinosum
Where does the middle meningeal artery divide into anterior and posterior branches?
- at pterion
What are the parts of the internal carotid artery?
- Cervical part
- Petrous part
- cavernous part
- cerebral part
Where does the petrous part lie?
- follows carotid canal of petrous part of temporal bone
Where does the cavernous part lie?
- carotid groove of the body of the sphenoid bone
Where does the cerebral part lie?
- inferior surface of the brain
What is the carotid siphon?
- u-shaped portion of internal carotid artery
- formed partially by cavernous and cerebral parts
What is the origin of the ophthalmic artery?
- branch of carotid siphon –> internal carotid artery –> common carotid artery
In the circle of willis, what arteries do the internal carotid arteries contribute to?
- anterior cerebral arteries
- middle cerebral arteries
- posterior communicating arteries
What does the union of the vertebral arteries form?
- basilar artery
In the circle of willis, what arteries do the vertebral arteries contribute to?
- basilar artery
- posterior communicating artery
What percentage of blood that is ejected from the heart goes to the head?
- 20%
What are the arteries that link the cerebral arteries to form the circle of willis?
- anterior communicating
- posterior communicating (x2)
What percentage of people have a normal/complete circle of willis?
- 18%
What are two variations in the circle of willis?
- missing the anterior cerebral
- missing one of the posterior communicating
What fissure does the middle cerebral artery pass through?
- lateral fissure
What fissure does the anterior cerebral artery pass through?
- oblique fissure
What fissure does the posterior cerebral artery pass through?
-
What is the blood drainage of the head?
- internal jugular veins (x2)
- external jugular veins (x2)
- vertebral venous plexus
What is the vertebral venous plexus?
- a network of veins that wrap around the vertebral part of vertebral artery
What occurs at the internal occipital protrusion?
- confluence of sinuses
What is the blood flow of the venous sinuses into the internal jugular vein?
- occipital sinus and superior sagittal sinus
- confluence of sinuses
- transverse sinus
- sigmoid sinus
- internal jugular vein
What venous sinuses are located in the dura matter?
- superior sagittal sinus
- inferior sagittal sinus
- straight sinus
- transverse sinus
- sigmoid sinus
- cavernous sinus
- inferior and superior petrosal sinuses
What is the origin of the internal jugular veins?
- continuation of sigmoid venous sinus in jugular foramen
What is the termination of the internal jugular veins?
- both form a confluence with the subclavian vein to form the brachiocephalic vein
What is the superficial veins of the neck?
- external jugular veins (x2)
What is the origin of the external jugular vein?
- tributary of the subclavian vein
What does the external jugular vein drain?
- most of scalp and face
What does the external jugular vein course?
- superficial to sternocleidomastoid
What is the origin of the subclavian vein?
- is a continuation of an axillary vein at external edge of 1st rib
What does the subclavian vein course?
- anterior to subclavian artery
What are the two major tributaries of the subclavian vein?
- external jugular vein
- vertebral vein plexus
What is the termination of the subclavian veins?
- confluence with internal jugular vein to form a brachiocephalic vein
