Blood supply of the brain

Question 1

importance of blood to the brain

Answer 1

• The adult brain requires 750 mL(1 quart) of oxygenated every minute to maintain normal activity
• 20% of arterial oxygen is consumed by the brain
• Cessation of blood flow for 5-10 sec temporarily changes neural activity
• As little as 5 minutes without blood flow to the brain can cause irreversible neuronal damage

Question 2

Blood to the Brain is Carried out by 2 Pairs of Arteries

Answer 2

•Internal Carotid
–“Anterior Circulation”
•75% of CVAsoccur here (strokes)
•Vertebral
–“Posterior Circulation”

Question 3

Internal Carotid Artery Carries the Anterior Circulation

Answer 3

•One of the two terminal branches of the common carotid
•It has cervical, petrous, cavernous, and cerebral parts
–The cerebral part gives off the ophthalmic artery
•Terminates by dividing into ACA and MCA

gives off hypophyseal artery

Question 4

foramen lucerum ICA

Answer 4

is where it gets all funky

Question 5

cavernous ICA

Answer 5

region where occulomotor nerve runs also

Question 6

internal carotid branches

Answer 6

–Anterior Cerebral
–Middle Cerebral
–Ophthalmic
–Hypophyseal
–Anterior Choroidal
–Posterior Communicating

Question 7

Anterior cerebral artery

Answer 7

ACA covers medial surface of the cerebral cortex

Recurrent artery of Heubner, goes inside the brain to the subcortical

Question 8

middle cerebral artery

Answer 8

75% of lateral surface is covered by the medial artery

Lencticulostriate

lateral surface of frontal parietal and temporal lobe

Question 9

what artery has branches in the isle of reil

Answer 9

MCA

Question 10

arteries of sudden death

Answer 10

MCA and ACA gives rise to

lateral lentidulostriate

medial lenticulostriate

Question 11

Vertebro-basilar system

Answer 11

most likely to have a surviving stroke in anterior circulation

posterior circ has arteries going to brainstem and you die if you stop it

Question 12

Basilar artery

Answer 12

ends by dividing into the posterior cerebral arteries(PCA) at the superior end of the pons. The basilar artery also gives
–superior cerebellarartery
–pontinearteries
–labyrinthine artery
–anterior inferior cerebellar artery (AICA)

Question 13

labyrinthine artery

Answer 13

can come from a lot of places

goes to inner ear, vesitbular apparatus and cochlea

Question 14

vertebral arteries

Answer 14

Vertebral arteries enter the foramen magnum and unite at the caudal end of the pons to form the basilar artery

posterior circulation

Question 15

Circle of Willis Connects the Anterior and Posterior Circulations

Answer 15

Also, helps prevent complete blockage if one area is blocked
–Internal carotid artery circulation can use contralateralcirculation

But only about ½ these circles look like they do. Lots of anatomical variation here.

Question 16

posterior cerebral

Answer 16

basilar branch

supplies mostly medial portion or temporal and occipital

supplies ventral surgace of temporal lobes and crus cereri (carries upper motor neurons) or cerebral pudencles of midbrain

Question 17

thalamoperforating arteries

Answer 17

from pca also supply the thalamus

Question 18

radicular arteries

Answer 18

supply spinal cord

Question 19

artery of adamkiewicz

Answer 19

great ventral radicular artery

most important radicular

Question 20

lateral lenticulostriates

Answer 20

from mca

Question 21

lenticulostriates

Answer 21

supply basal ganglia

Question 22

medial lenticulostriates

Answer 22

from aca

Question 23

thalamoperforating arteries

Answer 23

from posterior cerebral

Question 24

midbrain is supplied by

Answer 24

posterior cerebral

Question 25

soft spots in arteries

Answer 25

come from where the artery changes or branches | good chance of hemorrhage

Question 26

cerebrovascular accidents are concentrated

Answer 26

at branchpoints in ant circulation

Question 27

infarct (umbra)

Answer 27

``` necrosis of tissue due to lack of blood supply uncontrolled cell death black on ct beyond repair from stroke ```

Question 28

prenumbra

Answer 28

``` peri-infarct zone apoptosis controlled cell death possible recovery grey still have hope from stroke ```

Question 29

symptoms from aca stroke

Answer 29

weakness and paralysis opposite and lower half of body | bladder dysfunction

Question 30

aca stroke around corpus colloum

Answer 30

can you drive with one eye open?

Question 31

symptoms from pca storke

Answer 31

occipital lobe cant see contralaterally hemianopsia

Question 32

mca stroke symptoms

Answer 32

hemiparesis (with or without hemisensory deficit) mainly affecting the arm and face wernickes aphasia

Question 33

angiography

Answer 33

suspected stroke or hematoma

Question 34

increase neural activity

Answer 34

increase metabolism, see by glucose uptake (PET) or o2 uptake (fMRI)

Question 35

the bold signale

Answer 35

fMRI, blood oxygen diff. | inactivated at first then activate and see the difference

Question 36

BBB

Answer 36

1. controls molecular traffic, keeps out toxins 2. contributes to ion homeostasis for optimal neural signaling (main reason so ap do not get messed upped 3. maintains low protein environment in CNS, limits proliferation, preserves neural connectivity 4. separates central and peripheral neurotransmitter pools, reduces cross-talk, allows non-synaptic signaling in CNS 5. allows immune surveillance and response with minimal inflammation and cell damage.

Question 37

what can get through bbb tight junctions

Answer 37

oxygen

Question 38

where is bbb?

Answer 38

capillaries corpus callosum arachnoid

Question 39

tancytes

Answer 39

specialized ependymal cells that line the ventricles around CVOs

Question 40

parts w/0 bbb overview

Answer 40

so we can detect toxins, cell conc, o2, measure things in blood. sometimes open sometimes not

Question 41

areas w/o bbb

Answer 41

1. subfornical organ - blood osmolarity 2. organ vasculosum - salt 3. median eminence - hormones 4. area postrema - hormones, detects toxins, vomiting

Question 42

venous drainage of brain

Answer 42

* Thin-walled vessels in the subarachnoid space with no valves or muscle layer. * Pierce the arachnoid mater and meningeal layer of the duramater to drain into the duralvenous sinuses.

Question 43

trolard

Answer 43

connect the superior and inferior sagittal sinus'

Question 44

labbe

Answer 44

drains into the transverse sinus'

Question 45

superficial cerebral veins drains into the

Answer 45

superior saggital sinus

Question 46

deep cerebral veins drain into

Answer 46

straight sinus

Question 47

internal cerebral vein

Answer 47

deep veins drain here thento great cerebral vein of galen

Question 48

basal vein

Answer 48

ACTUALLY a superficial vein. HUGE variations in venous anatomy (hypoplasias)…most consistent in the deep cerebral veins

Question 49

venous drainage of medial cortex

Answer 49

Thalamostriate-septal meet internal c v at the venous angle, providing a landmark..Basal vein connects cavernous sinus and spheonparietal sinus to great vein of gale—straight sinus

Question 50

superior petrosal veins

Answer 50

on lateral cerebellum drain to transverse sinus

Question 51

pontine veins

Answer 51

anteromedian, anterolateral, and transverse

Question 52

spinal cord veins

Answer 52

anterior and posterior spinal and radicular veins