Vesicles to Ventricles

Question 1

ependyma and function

Answer 1

single layer of cells that lines the ventricles. Forms a leaky cell layer to allow exchange of CSF from interstitial space to ventricles.

Question 2

volume and rate of production of CSF per day

Answer 2

volume = 125 ml. 5oo ml is produced each day

Question 3

Describe composition of CSF. What happens to the composition of CSF as the ionic composition of plasma changes?

Answer 3

almost no change. composition is very similar to plasma and is tightly regulated.

Question 4

What produces CSF?

Answer 4

specialized tissues in the ventricles called choroid plexus

Question 5

How is CSF resorbed by arachnoid granulations?

Answer 5

controversial. either pinocytosis (transcellular vesicle transport) or by hydraulic pressure differences between the CSF and venous sinuses.

Question 6

non-communicating hydrocephalus and where this happens

Answer 6

flow of CSF is interrupted. obstruction of interventricular foramen or of the cerebral aqueduct.

Question 7

communicating hydrocephalus

Answer 7

CSF gets to subarachnoid space but isn’t resorbed properly.

Question 8

brain regions supplied by the anterior circulation system/ICA

Answer 8

anterior half of the brain, including the entire cerebral hemisphere except for the medial part of the occipital lobe and the inferior part of the temporal lobe

Question 9

brain regions supplied by the posterior circulation system/vertebral arteries

Answer 9

brainstem, cerebellum and some cortex (medial face of the occipital lobe and inferior temporal lobe)

Question 10

brain regions supplied by the ACA

Answer 10

anterior 2/3s of the MEDIAL face of the cerebral hemisphere, and the orbital cortex

Question 11

brain regions supplied by the MCA

Answer 11

lateral face of the cerebrum including frontal, parietal and temporal lobes. Also gives off branches that supply the deep white and gray matter of the cerebral cortex.

Question 12

brain regions supplied by the PCA

Answer 12

medial face of the occipital lobe and the inferior surface of the temporal lobe

Question 13

brain regions supplied by the PICA

Answer 13

wraps around the medulla and supplies the most caudal part of the cerebellum + choroid plexus of 4th ventricle

Question 14

brain regions supplied by the AICA

Answer 14

anterior/inferior face of the cerebellum + middle cerebellar peduncle + inferolateral portion of the pons

Question 15

brain regions supplied by the SCA, superior cerebellar artery

Answer 15

superior half of cerebellum + parts of the midbrain

Question 16

how do the ventricles communicate with the CSF

Answer 16

2 lateral apertures (foramen of luscka) and caudal aperture. see FA 468.

Question 17

cisterna magna

Answer 17

cistern located between the cerebellum and dorsal surface of medulla oblongata

Question 18

cisterns

Answer 18

openings in the subarachnoid space that allow flow of CSF

Question 19

interpeduncular cistern

Answer 19

wide cavity where the arachnoid extends across between the 2 temporal lobes. Encloses the cerebral peducles and contains the arterial circle of willis.

Question 20

Describe the relationship between ependymal cells and capillaries in the choroid plexus

Answer 20

In choroid plexus, brain capillaries lose their tight junctions and the ependymal cells acquire tight junctions. Thus solutes diffuse out of capillaries but then must be actively transported across the ependymal cell to get into the CSF (typical epithlial cell transporters: Na/K, Na-proton exchanger, HCO3-Cl, Na-K-Cl)

Question 21

how is CSF formed by choroid plexus?

Answer 21

fluid is secreted from capillaries adjacent to ependymal cells and actively transported across ependymal cells. This occurs within specialized ependymal cells in the choroid plexus that have tight junctions.

Question 22

what do the anterior and posterior spinal arteries supply?

Answer 22

rostral part of the spinal cord.

Question 23

deep structures are drained though inferior sagittal sinus. superficial structures are drained through the superior sagittal sinus.

Answer 23

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