Blood Supply To The Brain

Question 1

Two arterial systems supply the brain:

Answer 1

Internal carotid arteries (80%)
Vertebral arteries (20%)

Question 2

What does the internal carotid arteries supply

Answer 2

Most of telencephalon and diencephalon

Question 3

What does the vertebral arteries supply

Answer 3

• brainstem
• cerebellum
• parts of diencephalon
• spinal cord
• occipital and temporal lobes

Question 4

Has a cervical and intracranial part and ascends through side of the neck until it reaches the temporal bone, where it veers anteriorly

Answer 4

Internal carotid artery

Question 5

In the carotid canal, the internal carotid gives this small branch

Answer 5

Ramus caroticotimpanicus

Question 6

How does the internal carotid artery enter the skull

Answer 6

Traverses the temporal bone, entering the skull through the carotid canal

Question 7

What is the first branch of the internal carotid artery

Answer 7

Ophthalmic artery

Question 8

How does the internal carotid artery run through skull

Answer 8

Passes through the cavernous sinus and he subarachnoid space at the base of the brain

Question 9

How does the ophthalmic branch of internal carotid artery leave skull

Answer 9

Through the superior optic foramen

Question 10

What artery does the ophthalmic artery give rise to

Answer 10

Central retinal artery

Question 11

As the internal carotid artery proceeds alongside the optic chiasm, what other branches does it give off?

Answer 11

The anterior choroidal artery and the posterior communicating artery

Question 12

What does the internal carotid turn into and continue as?

Answer 12

MCA

Question 13

What is the first branch off of the MCA

Answer 13

ACA

Question 14

How does the ACA run

Answer 14

Medically, superior to the optic nerve and enters the longitudinal fissure

Question 15

How are the two ACA connected

Answer 15

Near their entrance into the longitudinal fissure, are connected by the anterior communicating artery

Question 16

What happens to the ACA after the connection with the anterior communicating artery

Answer 16

Enters the longitudinal fissure and curves around the corpus callosum

Question 17

What does ACA supply

Answer 17

Medial parts of the frontal and parietal lobes

Question 18

What does ACA branch into

Answer 18

• callosomarginal artery follows the cingulate sulcus

- continues as the pericallosal artery which stays immediately adjacent to the corpus callosum

Question 19

Occlusion of ACA

Answer 19

Causes restricted contralateral motor and somatosensory deficits affecting the leg more than other parts of the body

Question 20

MCA after the cavernous sinus

Answer 20

Proceeds posteriorly in the lateral sulcus, divides into a number of branches that supply the insula, emerges from the lateral sulcus and spread out to supply most of the lateral surface of the cerebral hemisphere

Question 21

Occlusion of MCA

Answer 21

Causes major motor and somatosensory deficit especially in upper body and hand

Question 22

The segments of the MCA and what occlusions mean there

Answer 22

The lower the number, the more proximally the artery gets occluded and more serious the consequences

Question 23

How many branches does the MCA give rise to

Answer 23

12 that supply deep structures of the diencephalon and telencephalon

Question 24

What are the branches of the MCA that supply the deep structures of the diencephalon and the telencephalon

Answer 24

Lenticulostriate arteries

Question 25

Where are perforating arteries (lenticulostriate) numerous

Answer 25

Adjacent to optic chiasm and in area between the cerebral peduncles. These areas areas are called the anterior and posterior perforated substances

Question 26

How do the vertebral basilar arteries run

Answer 26

- Rostral (up) through the foramina of the lateral processes of the spinal vertebrae - enter the skull cavity through the foramen magnum - fuse between the medulla and pons to form basilar artery

Question 27

What foramen does vertebral arteries run through

Answer 27

Magnum

Question 28

Branches of the vertebral arteries

Answer 28

- posterior spinal artery - anterior spinal artery - posterior interfering cerebrally artery (PICA)

Question 29

Runs caudally along the posteriolateral aspect of the spinal cord and supplies the posterior third of that half of the cord

Answer 29

Posterior spinal artery

Question 30

Joins its counterpart from the opposite side, forming a single anterior spinal artery that runs caudally along the anterior midline of the spinal cord supplying the anterior two third of the cord

Answer 30

Anterior spinal artery

Question 31

Branches of the basilar artery

Answer 31

- numerous unnamed branches - anterior inferior cerebellar artery (AICA) - superior cerebellar artery (SCA)

Question 32

At the level of the midbrain, what does the basilar artery bifurcate into

Answer 32

The two posterior cerebral arteries (PCA)

Question 33

What supplies the thalami

Answer 33

Perforating branches of the posterior cerebral artery

Question 34

What supplies the choroid plexus of the third and the lateral ventricle

Answer 34

Choroidal branches of the posterior cerebral artery

Question 35

What are the cortical branches of the posterior cerebral artery

Answer 35

- anterior temporal - posterior temporal - lateral occipital - medial occipital

Question 36

What supplies the visual cortex

Answer 36

The medial occipital branch of the posterior cerebral artery

Question 37

What does the lateral artery of the posterior cerebral artery branch into

Answer 37

Anterior, middle, and posterior inferior temporal arteries

Question 38

What does the circle of willis connect

Answer 38

The internal carotid and the vertebral basilar systems

Question 39

What completes the arteries life polygon known as the circle of willis

Answer 39

The posterior cerebral artery is connected to the internal carotid by the posterior communicating artery

Question 40

Communicating arteries and alternate routes

Answer 40

The communicating arteries vary in size and more often are not sufficient to ensure functional anastomoses

Question 41

How does the circle of willis look in different people

Answer 41

Asymmetries are common

Question 42

Venous drainage of the brain

Answer 42

Between inner and outer layers of the dura mater - receive blood from brain as wells as CSF from subarachnoid space - collected by dural venous sinuses - these drain into internal jugular

Question 43

Valves in CNS veins

Answer 43

None

Question 44

Process where cerebral blood vessels act to maintain constant flow

Answer 44

Autoregulation

Question 45

Cerebral angiogram

Answer 45

- dye - catheter into femoral artery, threading it up to aorta, to artery of choice - rapid series of X ray pics