ICL 2.6: Cerebrospinal Fluid, Ventricular System & Hydrocephalus

Question 1

where are the lateral ventricles located?

Answer 1

lateral ventricles van be found in all lobes of the brain

it has an anterior horn, body and posterior and inferior horns

Question 2

which nuclei protrudes out into the lateral ventricle?

Answer 2

the head of the caudate nucleus

the lateral ventricle is right next to the basal ganglia!

Question 3

T2 weighted imaged, what color is the CSF?

Answer 3

super bright white

Question 4

what connects the lateral ventricle with the 3rd ventricle?

Answer 4

intraventricular foramen

Question 5

what forms the walls of the 3rd ventricle?

Answer 5

the diencephalon

Question 6

where is the 4th ventricle located?

Answer 6

the apex of the ventricle extends into the base of the cerebellum

caudally it tapers into a narrow channel that continues into the cervical spinal cord as the central canal

the floor of the fourth ventricle is the rhomboid fossa which is formed by the pons and medulla

Question 7

what are the only naturally occurring openings between the ventricles of the brain and the subarachnoid space surrounding the space?

Answer 7

1. foramina of Luschka
2. foramina of Magendie

these are both in the 4th ventricle

Question 8

what are cisterns?

Answer 8

part of the subarachnoid space where larger pockets of CSF flow

there are specific names for the different cisterns

ex. interpeduncular cistern
ex. prepontine cistern
ex. superior cistern
ex. cerebellomedullary cistern

Question 9

what is CSF?

Answer 9

it surrounds the brain and spinal cord

90% of it is in the subarachnoid space; only 10% is in the ventricles

Question 10

what is the function of CSF?

Answer 10

1. shock absorber for CNS
2. nutrition
3. immune system control
4. buoyancy of the brain
5. cooling

Question 11

what is the choroid plexus?

Answer 11

a collection of tissue in a series of folds each with single layer of cuboidal cells surrounding a core of connective tissue

choroid epithelial cells are joined by tight junctions

they produce CSF

Question 12

what are ependyma?

Answer 12

ventricles of the brain and central canal of the spinal cord are lined with simple cuboidal epithelium called ependyma

it contains lots of mitochondria, microvilli, cilia

the ependymal cells are attached by zonulae adherence = desmosomes

Question 13

is there fluid exchange of CSF in the brain?

Answer 13

yeah sometimes

the composition of CSF can indicate disease processes because of this

Question 14

where is the CSF produced?

Answer 14

in the brain, 80% of the CSF is produced by the choroid plexus in the lateral ventricles as well as the 3rd and 4th ventricles

the rest is produced in the interstitial space

there’s also some produced by the dura mater that encases the spinal cord

Question 15

what are arachnoid vili?

Answer 15

aka granulations

part of the arachnoid layer of meninges protrudes into the superior sagittal sinus and they’re important in reabsorption of the CSF

arachnoid villi are structurally adapted for the transport of CSF from the subarachnoid space into the venous circulation

the flow is only from the villus into the sinus = unidirectional

Question 16

what is hydrocephalous?

Answer 16

abnormal accumulation of CSF within ventricles and subarachnoid space

often leads increase ventricular size and may lead to increase in intracranial pressure

most due to interruption of CSF flow and almost never due to higher production

symptoms = headache, lethargy, loss of coordination of balance, impaired vision etc.

Question 17

what is communicating hydrocephalous?

Answer 17

occurs when CSF flows out of the ventricle and into the spinal canal but it is NOT reabsorbed by the arachnoid villi

Question 18

what is non-communicating hydrocephalous?

Answer 18

occurs when CSF flows does not flow properly between or out of the brain ventricles because of an obstruction