Vasculature of CNS

Question 1

two routes to get blood to cranial vault

Answer 1

internal carotid arteries 2x left and right

vertebral arteries 2x left and right

Question 2

internal carotid system

Answer 2

enter skull at carotid canal

join cerebral arterial circle

Question 3

branches of cerebral arterial circle

Answer 3

three cortical branches

off of these three - deep perforating branches

Question 4

branches of internal carotid

Answer 4

middle cerebral a.
posterior communicating a.
anterior cerebral a.

Question 5

lenticulostriate arteries

Answer 5

deep penetrating arteries
lentiform and striatum nuclei (basal nuclei)

branches of middle cerebral arteries

Question 6

anterior cerebral artery

Answer 6

runs in longitundinal fissure and above corpus callosum

left and right 2x

Question 7

corpus callosum

Answer 7

connects L and R cerebral hemispheres

Question 8

vertebral arteries

Answer 8

enter cranium vault via foramen magnum

-meet as basilar artery

Question 9

basilar artery

Answer 9

where vertebral arteries come together

Question 10

branches of basilar artery

Answer 10

posterior cerebral arteries

Question 11

posterior inferior cerebellar artery

Answer 11

first large branch off of vertebral arteries

-serves posterior / inferior cerebellum

Question 12

anterior inferior cerebellar artery

Answer 12

second large branch off of vertebral arteries

Question 13

superior cerebellar artery

Answer 13

branch off of basilar artery

Question 14

pontine arteries

Answer 14

branches of basilar artery

-blood to pons

Question 15

posterior spinal artery

Answer 15

arises off of vertebral artery or posterior inferior cerebellar artery

Question 16

anterior spinal artery

Answer 16

single artery that arises from both vertebral arteries

Question 17

blood brain barrier

Answer 17

physiologic barrier between intravascular space and CNS ECF

in brain and spinal cord

Question 18

two major types of capillaries

Answer 18

continuous and fenestrated

Question 19

continuous capillaries

Answer 19

in CNS
no pores or fenestrations
tight junctions between endothelial cells

endothelial cells lining capillaries that form blood brain barrier

Question 20

components of blood brain barrier

Answer 20

capillary lined by endothelial cells (continuous)
-tight junctions between them

astrocyte end feet
-do NOT form blood brain barrier

Question 21

what can cross blood brain barriers

Answer 21

small molecules (< 400 daltons)
insulin - 6,000 daltons - cannot pass without transporter

also, gas can diffuse and lipid soluble mlcs

Question 22

ventricular space

Answer 22

fluid filled spaces within brain
developmental remnant of neural tube

4 in brain - continuous with central canal to SC

Question 23

subarachnoid space

Answer 23

continuous with the ventricles of brain

surrounds brain and spinal cord
fluid filled

Question 24

choroid plexus

Answer 24

site of CSF production

Question 25

ventricle lining

Answer 25

ependymal cells | -ciliated and can move fluid

Question 26

ventricles

Answer 26

2x lateral third ventricle fourth ventricle

Question 27

lateral ventricle division

Answer 27

``` anterior horn body posterior horn inferior horn trigone ```

Question 28

interthalamic adhesion

Answer 28

in third ventricle | -connecting left and right thalamus

Question 29

aqueduct of midbrain

Answer 29

from third ventricle to fourth ventricle aka mesencephalic aqueduct

Question 30

apertures

Answer 30

openings in 4th ventricles to subarachnoid space

Question 31

separation of lateral ventricles

Answer 31

septum pellucidum

Question 32

central canal

Answer 32

continuous with fourth ventricle to spinal cord

Question 33

connection of lateral and third ventricle

Answer 33

interventricular foramen 2x

Question 34

boundaries of lateral ventricles

Answer 34

``` roof - corpus callosum floor - diencephalon lateral walls - caudate nucleus** roof of inferior horn - tail of caudate nucleus floor of inferior horn - hippocampus ```

Question 35

boundaries of third ventricles

Answer 35

lateral walls - diencephalon | floor - optic chiasm and infundibulum

Question 36

mesencephalic aqueduct

Answer 36

no choroid plexus - no CSF production good site for occlusion

Question 37

boundaries of 4th ventricles

Answer 37

roof - cerebellum | floor - pons/medulla

Question 38

openings of subarachnoid space

Answer 38

from 4th ventricle 1x median 2x lateral

Question 39

CSF

Answer 39

produced from blood protects CNS - buoyancy (decreases weight) and serve as ECF also a possible lymphatic function pH influence on respiratory centers

Question 40

CSF production

Answer 40

active - uses ATP to transport ions passive - water follows ions selective - pick out constituents in blood we want 500mL / day

Question 41

reabsorption of CSF

Answer 41

passive - dependent on pressure gradient

Question 42

choroid plexus

Answer 42

roof of every ventricle | -2x lateral, third, fourth

Question 43

choroid epithelium

Answer 43

continuous with ependymal cells lining ventricles -modified ependymal cells has tight junctions forms blood CSF barrier

Question 44

capillaries to choroid plexus

Answer 44

surrounded by choroid epithelium fenestrated capillaries

Question 45

anterior choroidal artery

Answer 45

main artery supplying choroid plexus

Question 46

free exchange

Answer 46

between capillary and choroid epithelium

Question 47

arachnoid granulations

Answer 47

reabsorption of CSF to venous sinus system have one way valves - pressure dependent

Question 48

hydrocephalus

Answer 48

CSF production is active -independent of pressure water in brain -occlusion of CSF flow

Question 49

occlusion of interventricular foramen

Answer 49

results in huge lateral ventricles

Question 50

hydrocephalic shunt

Answer 50

drain CSF - commonly to peritoneum for absorption