Ventricles Flashcards
Cerebrospinal fluid (CSF) is secreted by:
- the choroid plexuses, highly vascularized tissue found in the ventricles of the brain.
Label all:
Choroid plexuses:
- produce CSF
- highly vascular
- sit on top of ventricles
Where is CSF located?
- ventricles
- subarachnoid space of the brain and spinal cord
What connects the lateral ventricles to the third ventricle?
Interventricular Foramen
What connects the third ventricle to the fourth ventricle?
cerebral aqueduct (of Sylvius)
Fourth ventricle CSF mostly enters the subarachnoid space through what three openings:
- two lateral foramina (of Luschka)
- one median foramen (of Magendie)
CSF is resorbed into the venous system at the superior sagittal sinus via:
arachnoid granulations
Arachnoid granulations:
- projections of arachnoid that come into close contact with the dural wall of the superior sagittal sinus to allow for the passage of CSF from the subarachnoid space to the venous system via the superior sagittal sinus.
Choroid plexuses produces how much CSF per day?
- about 500ml a day, but we only have about 150ml in us at any given moment. CSF is constantly being absorbed into the venous system - this is nonvascular circulation.
An abnormal increase in intracranial CSF pressure results in:
hydrocephalus
The two major categories of hydrocephalus:
- communicating hydrocephalus
- non-communicating (or obstructive) hydrocephalus.
Communicating hydrocephalus:
- resorption of CSF into venous system does not keep pace with production of CSF.
- problem is at level of meninges.
Non-communicating or obstructive hydrocephalus:
- CSF produced in the ventricles is obstructed in its passage to the subarachnoid space and therefore there is diminished resorption into the venous system.
- Problem is at level of ventricles.
Most common site of obstruction in non-communicating or obstructive hydrocephalus:
cerebral aqueduct
