Foundation - The Choroid Plexus

Question 1

Why do we need the choroid plexus

Answer 1

Need water from the blood

Question 2

how many choroid plexui are there

Answer 2

4 - one for each ventricle

Question 3

choroid plexus contains ___ and is the main ____

Answer 3

the B-CSF barrier

Main source of CSF
main/One of the primary gateways of immune cell entry into CNS

Question 4

choroid plexus folds within

Answer 4

the pia matter

Question 5

every Choroid plexi has ___
every fold has _____

Answer 5

have same morphology
every fold has own capillary

Question 6

Choroid plexi transporters

Answer 6

Question 7

Choroid plexi development

Answer 7

more organized
nucli move down
inc folds (microvilli - also own little folds)
each fold - own capillary
make tight junctions (are special epithelial cells)

Question 8

CSF flow

Answer 8

lateral
interventricular foramina
third
cerebral aqueduct
fourth
central canal (into spinal cord) and
median/lateral apertures
(into subarachnoid spaces - now multidirectional flow)

Question 9

What generates CSF flow?

Answer 9

1. Beating cilia
2. Pulsations on vessels from heartbeat
3. Constant generation from one side and absorption on another
4. A combinations of any of the above

Question 10

If normal flow of CSF is interrupted

Answer 10

brain will be damaged

Congenital – can go unnoticed for years
* Babies skulls are flexible
* Treatable with drainage tube

Acquired – (infections, tumors) very serious, no room for expansion in the brain
* Surgery
* Need to treat the cause, not the consequence

Question 11

Reabsorption of CSF

Answer 11

granulations (arachnoid villi) - like a valve
dec pressure - close
inc pressure (thus in CSF) - open -drainage - maintain intracranial pressure

Question 12

spinal vs arachnoid villi

Answer 12

arachnoid - drain into jugular

spinal - drain into cervial nodes and other lympatic nodes

Question 13

Conditions that inc. CSF volume

Answer 13

obstrution of valve
too much clorid plexi - too much growth - cancer
stroke - inc inflamaition (or infection) - obstruct flow

Question 14

Conditions that dec. CSF volume

Answer 14

leaky valves
cell death (damge, autoimmune) to epidymal cells
severe dehydration
CSF leaks

Question 15

barriers of the brain that allow entryways for immune cells (and pathogens)

Answer 15

BBB
BCSFB
BMB

Question 16

T cells or B cells

Answer 16

none in the parenchyma (only microglia) (under steady state conditions)

but there is a lot on the surface - patrol the surfaces of the brain (menengial layers) (despite low numbers)

main way get in - chlorid plexi

Most immune cells in the brain are resident effector cells (i.e. perivascular macrophages)

Question 17

How do immune cells get in BCSFB

Answer 17

1. They migrate across the fenestrated endothelium into the stromal space
2. They move along the basal surface of the ependymal cells
3. They cross into the CSF-filled ventricle (either paracellularly or transcellularly)

Question 18

The glymphatic system is formed by

Answer 18

the flow of the CSF and ISF (interstitial fluid - water comes out of blood) through channels inside the brain

Channels are formed by astrocytes

Question 19

Glymphatic system based on similarities to

Answer 19

lymphatics but is driven by glia (astrocytes)

Question 20

Aquaporin-deficient mice develop pathology

Answer 20

similar to Alzheimer

Question 21

Glymphatic system is most active

Answer 21

while asleep
(One of two plumbing systems)

Question 22

flow of glympatic system

Answer 22

spreads glucose
removes waste - into space with immune cells - can see