Blood Supply To Brani

Question 1

Importance of arterial blood supply to the brain

Answer 1

Needs a continuous supply of oxygenated blood and glucose as a primary energy source

Question 2

Lobes of the cerebral cortex

Answer 2

Parietal, frontal, occipital, temporal

Question 3

Subcortical structures of the brain

Answer 3

Diencephalon - thalamic masses and basal ganglia
Mesencephalon
Pons
Medulla
Cerebellum

Question 4

5 branches of aortic blood supply

Answer 4

Aortic root (supplies blood to heart)
Ascending aorta
Arch of aorta
Descending aorta
Abdominal aorta

Question 5

3 branches of the apex of the aortic arch

Answer 5

Braciocephalic trunk/artery
Left common carotid
Left subclavian

Question 6

What does the brachiocephalic artery divide into?

Answer 6

Right subclavian artery
Right common carotid artery

Question 7

Where does the brachiocephalic artery bifurcate?

Answer 7

Level of the sternoclavicular articulation

Question 8

What do the common carotid arteries supply?

Answer 8

Right supplies the right side of neck and right anterior cerebral circulation
Left supplies the left side of neck and left side of cerebral circulation

Question 9

What level does the arch of the aorta sit?

Answer 9

T4/T5 discs at the sternal angle of Louis

Question 10

When does bifurcation of the common carotid occur?

Answer 10

Superior part of thyroid cartilage, roughly c3/4 vertebral levels

Question 11

What does internal carotid supply?

Answer 11

No branches in the neck, branches constitute the anterior cerebral circulation

Question 12

How do distinguish internal and external carotid

Answer 12

Internal has a dilation at the start (carotid sinus) and has no branches in the neck

Question 13

What does the external carotid artery supply?

Answer 13

Neck, face, scalp, mouth and jaw tissues

Question 14

What are the branches of the external carotid artery?

Answer 14

SALFOPMS - some anatomists like freaking out poor medical students
Superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, maxillary, superficial temporal
Last 2 are terminal branches

Question 15

4 segments of the ICA

Answer 15

Cervical, petrous, cavernous, cerebral

Question 16

What else does the ICA carry with it?

Answer 16

Sympathetic supply to the head region

Question 17

What are the 3 major branches of the ICA

Answer 17

Anterior cerebral artery, middle cerebral artery, posterior communicating artery

Question 18

What are the 2 terminal minor branches of the ICA?

Answer 18

Anterior choroidal artery, ophthalmic artery

Question 19

What does the anterior cerebral artery supply?

Answer 19

Smaller major branch of ICA. Supplies frontal and parietal lobes. Runs through head like Mohawk. Joined by anterior communicating artery.

Question 20

What does the middle cerebral artery supply?

Answer 20

2/3 of the flow. Frontal parietal and occipital cortex.
Lateral striate arteries supply the basal ganglia.

Question 21

Where do most strokes occur in the brain?

Answer 21

Middle cerebral artery territory

Question 22

What does the posterior communicating artery supply?

Answer 22

Posterior circulation. Supplies midbrain, thalamus, temporal and occipital lobes of cortex.

Question 23

Describe the route of the ICA

Answer 23

Up (from below skull) into the carotid canal. Gives off caroticotympanic branch to the ear. Courses through the top of the foramen lacerum. Forwards into the cavernous sinus, and gives off inferior hypoohyseal branch. Moves medial to the anterior clinoid process, giving off the ophthalmic branch. Back on the roof of the cavernous sinus, giving off superior hypophyseal and anterior choroidal branches. Upwards to terminate as 3 major terminations.

Question 24

What is the circular arterial anastomosis of the brain?

Answer 24

Circle of Willis

Question 25

What is the purpose of the circle of Willis?

Answer 25

Allows for any disruption to blood supply along the anastomosis without loss of function due to the circular arrangement allowing perfusion on any part of the brain.

Question 26

Why are strokes still possible?

Answer 26

Because only 20-30% of people have a fully formed circle of Willis.

Question 27

Where is the circle of Willis located?

Answer 27

Within the subarachnoid space. Sits below the brain, forming the floor on which the brain rests upon.

Question 28

Anterior circulation of the circle of Willis

Answer 28

ICA, MCA, ACA, PCommA

Question 29

Posterior circulation of the circle of Willis

Answer 29

PCA, BA, VA

Question 30

Where do vertebral arteries arise from and what do they branch?

Answer 30

Arise from the subclavian arteries Largest branch - posterior inferior cerebellar artery Other branches - spinal artery

Question 31

What forms the basilar artery?

Answer 31

Formed by the union of the left and right vertebral arteries at the pinto-medullary junction.

Question 32

What does the basilar artery supply?

Answer 32

Most of the brainstem

Question 33

What branches does the basilar artery give off?

Answer 33

Gives for superior and anterior inferior cerebellar arteries Bifurcates into 2 posterior cerebral arteries

Question 34

What does the venous system of the brain drain?

Answer 34

CSF and blood

Question 35

What is the most superficial vein of the brain and where does it course?

Answer 35

Superior sagittal sinus. Runs along the superior border of the falx cerebri and drains into the confluence of sinuses.

Question 36

What is the main deep vein of the brain and how does it course?

Answer 36

Great vein of Galen. Joined by the inferior sagittal sinus and drains into the straight sinus to join the confluence of sinuses.

Question 37

What does the confluence of sinuses split into?

Answer 37

Confluence of sinuses splits into 2 transverse sinuses, which drain into the sigmoid sinus before draining into the internal jugular vein.

Question 38

What does the cavernous sinus drain?

Answer 38

Drains the superior and inferior ophthalmic veins from the superior orbital fissure, as well as the superficial middle cerebral vein and sphenoparietal sinuses.

Question 39

What are the veins of the infratemporal fossa?

Answer 39

Maxillary vein Superior ophthalmic veins, anterior intercavernous sinus, inferior ophthalmic vein, pterygoid venous plexus, middle meningeal vein

Question 40

What is stroke?

Answer 40

Clinical syndrome of abrupt loss of focal brain function lasting more than 24 hours that is due to either spontaneous haemorrhage into brain substance or inadequate blood supply to part of the brain (thrombosis, embolism)

Question 41

What is transient ischaemia attack TIA?

Answer 41

Sudden onset, focal disturbance of brain function, presumed to be of vascular origin. Resolves completely within 24 hours.

Question 42

Why might infection of the pterygoid region be of danger to the eye?

Answer 42

Pterygoid venous plexus lies deep in the temporal fossa is connected with the ophthalmic and anterior facial veins. This plexus drains into the cavernous sinus and so pus within the venous plexus may cause direct increased ophthalmic venous pressure or may even lead to a cavernous sinus thrombosis, resultant paralysis of extraocular muscles.