Ventricular System of the Brain?

Question

Where in the Cerebral Ventricular System you can find the 1st and 2nd Ventricles? Are the lateral ventricles intially considered as the 1st and 2nd Ventricles? Why don't the neuroanatomists consider the ventricles naming as Mesencephalonic Ventricle, Thalamic Ventricle, and the Lateral Ventricles? What is the reason? Are these ventricles the location of the flow of the Cerebrospinal fluid?

Answer 1

Embryologically, the entire ventricular system is derived from the inside of the neural tube. By convention, there is nothing in the ventricular system called the first or second ventricles.

I suppose the reason they are not named the mesencephalonic, thalamic and lateral ventricles is for historical reasons. The anatomists who "discovered" them
named them as they are and the names have stuck.

The lateral ventricles extend into the frontal, temperal and occipital lobes while the 3rd ventricle is found at the level of the thalamus and the 4th is found at the level of the pons and medulla.

Cerebrospinal fluid is made in specialized regions of the roofs of all the ventricles. Here there are special groupings of capillaries called "choroid plexi" (singular: plexus). They deliver nutrients and oxygen and remove waste and carbon dioxide from the ventricles. CSF is made as it passes from the capillaries through the special wall of the ventricle (ependymal cell). Then the CSF fluid is made in the ventricular system but then leaves the ventricular system through aperatures (found at the level of the fourth ventricle) to enter the SUBARACHNOID layer. The subarachnoid layer is found just above the pial layer of the brain and spinal cord.

Since CSF is made continuously throughout the day, we need a mechanism for reabsorbing it back into our blood stream. To do this, we have specialized places (arachnoid granulations) where it is reabsorbed from the subarachnoid layer and allowed to re-enter the venous system.

I hope that I helped to answer your question, sorry if its too complicated!

Answer 2

i partly know the ans.1st n 2nd ventricles r present b/n the two thalami.the csf is absorbed by arachnoid villi present in the meninges.it flows through all the ventricles and finally enters the spinal cord.thus they r sites of flow.