In this note, we are going to discuss the anatomy and function of the ventricles of the brain and the fundamentals of cerebrospinal fluid circulation.
To put it simply, our central nervous system is a long tube filled with cerebrospinal fluid (or CSF). Various structures of the brain and spinal cord are attached to this tube, like clay.
In the spinal cord, this tube is called the central canal and has a more or less smooth shape, the shape of a tube.
And in the brain, it significantly extends and forms several communicating cavities, called ventricles.
Ventricles
So, almost every division of the brain has its own cavity, its own ventricle.
In the cerebral hemispheres, there are two lateral ventricles, one each in the left and right hemispheres.
Each lateral ventricle has three horns:
- anterior (or frontal)
- posterior (or occipital)
- and inferior (or temporal).
The next one, the third ventricle, is located in the diencephalon.
So the lateral ones are the first and second, and in the diencephalon, respectively, the third. In the midbrain is the cerebral aqueduct (or aqueduct of Sylvius).
And the fourth ventricle is located between the pons and medulla oblongata on one side and the cerebellum on the other side.
Cerebrospinal fluid
Now, it is important to understand how exactly cerebrospinal fluid circulates throughout the ventricles because there is a certain pattern of it. Cerebrospinal fluid is produced by the choroid plexuses, which are present in all parts of the ventricular system except for the aqueduct.
From the lateral ventricles, CSF flows into the third ventricle via the interventricular foramen (or foramen of Monro), which is located in each lateral ventricle.
From there, through the cerebral aqueduct, it flows into the fourth ventricle.
From the fourth ventricle, CSF enters the subarachnoid space via the three foramina (or apertures):
two lateral apertures of Luschka and one median aperture of Magendie.
Then, from the subarachnoid space, the cerebrospinal fluid is filtered or drained into the dural venous sinuses by the arachnoid granulations.
These are projections of the arachnoid mater through the dura mater and their largest cluster is located in the area of the superior sagittal sinus.
Ventricles of the brain
- central canal
- canalis centralis
- lateral ventricles
- ventriculi laterales
- anterior horn
- cornu anterius
- posterior horn
- cornu posterius
- inferior horn
- cornu inferius
- third ventricle
- ventriculus tertius
- cerebral aqueduct
- aquaeductus cerebri
- fourth ventricle
- ventriculus quartus
- cerebrospinal fluid
- liquor cerebrospinalis
- interventricular foramen
- foramen interventriculare
- lateral aperture (Luschka)
- apertura lateralis
- median aperture (Magendie)
- apertura mediana
- arachnoid granulations
- granulationes arachnoideae
