Cerebral ventricular system: characteristics and functions

The nervous system, that great orchestra conductor that lives inside us, is made up of various parts that interact with each other and are responsible for various functions. Thus, it also has systems that allow proper functioning, such as the ventricular system, which curiously is nothing more than a system of small reservoirs connected to each other; something like a ‘sewer system’.

Inside the skull is the brain, and within this, the cerebrum. The ventricular system, made up of four ventricles, is contained in the brain. This system is responsible for maintaining, protecting and giving structure to our brain.. Not everyone has heard of this system, but its importance is capital.

Throughout this article we will take a tour of the ventricular system to define what it consists of, distinguish each of its cavities and functions and explore some alterations related to it. Let’s get started!

What is the ventricular system and what is its origin?

The set of cerebral ventricles is called the ventricular system. It’s about a system composed of structures, like cavities, connected to each other. Within them, cerebrospinal fluid (CSF) originates and circulates, a transparent liquid that bathes the brain and spinal cord.

The ventricular system develops in parallel with the rest of the central nervous system, facilitating the circulation of CSF during the process. Around day 26 of embryonic development, differentiation of the optic ventricle begins; Subsequently, an outpouching begins to occur in the midline of the midbrain, which will later form the cerebral aqueduct.

Towards the 6th week, the development of the interventricular foramen begins, beginning the formation of the choroid plexuses of the lateral ventricles. Then, the grooves and segmentation become more noticeable.

Subsequently, growth of the medial and lateral ventricular eminence occurs and the spherical shape of the lateral ventricle begins to resemble a C. The horns of the lateral ventricles thus begin to be pronounced; In addition, a small sac forms in the diencephalic floor that will be the 3rd ventricle. Meanwhile, the choroidal sacs of the 4th ventricle advance in their formation.

Finally, During weeks 7 and 8, the horns finish defining themselves and the definitive vesicular shape is formed. The isthmic part is compressed by the growing cerebellum and numerous villi extend in the midline.

Structure

The ventricular system is made up of four ventricles interconnected with each other through channels and openings. Let’s look at each of its parts:

Lateral ventricles (first and second ventricle). They are located in both cerebral hemispheres and have an anterior horn that faces the frontal lobe and a posterior horn that faces the temporal lobe. They connect through the third ventricle through the interventricular foramen of Monro. They are C-shaped and their volume increases throughout life.Third ventricle. It consists of a flattened and thin cavity that is located between the thalami and is crossed by the interthalamic commissure. Its connection with the rest of the system is through the Silvian cerebral aqueduct. It has two protuberances: the supraoptic recess, located above the optic chiasm, and the infundibular recess, which is located above the optic stalk.Fourth ventricle. It extends from the mesencephalic aqueduct to the central canal of the upper part of the spinal cord. Its floor is formed by the rhomboid fossa and communicates with the central canal through the foramina of Luschka and Magendie, from which the CSF exits into the subarachnoid space. Additionally, it connects with subarachnoid cisterns that allow CSF to reach the subarachnoid space.

Upon reaching the spinal cord, the ventricles continue through the ependymal canala cavity that begins at the end of the fourth ventricle and runs through the spinal cord internally until it ends in the first vertebra of the lumbar area.

Functions of the cerebral ventricular system

The ventricular system performs different tasks, as we see below:

CSF production. This is its main function, although it shares it with other structures, such as the subarachnoid space.Brain preservation. CSF helps maintain internal brain homeostasis, maintaining adequate intracranial pressure. In addition, this liquid helps eliminate waste, which allows the brain to maintain a suitable environment for its functioning.Brain buoyancy. Thanks to the CSF, the brain is floating, which contributes to the reduction of its weight from about 1,400 grams to about 50 grams.Defending. The CSF allows us to defend ourselves against external agents that could be dangerous for our brain. It also increases the degree of protection of our brain against trauma.

Alterations of the ventricular system

The ventricular system can suffer alterations of various types. Below we show some of them:

Hydrocephalus. This is a disorder in which there is an overproduction of CSF. As it evolves, it causes elevated intracranial pressure and can lead to brain atrophy, metabolic and cognitive disorders, and even death.Meningitis. It consists of inflammation of the meninges due to an infectious cause and is usually caused by viruses, fungi or bacteria. This inflammation produces an increase in intracranial pressure, hindering CSF circulation and leading to symptoms such as headaches, nausea, sensitivity to light, fever, and cognitive impairment, among others.Ventriculitis. It is the inflammation of the cerebral ventricles that increases intracranial pressure and alters the normal circulation of CSF and the correct functioning of the vascular system. It can be accompanied by hydrocephalus and produce, among other pathologies, encephalitis or inflammation of the brain.Alzheimer’s. As Alzheimer’s disease progresses, the deterioration and death of neurons increases, which causes a decrease in neuronal density. The space unoccupied by the subsequent decrease in volume is occupied by the ventricles, which expand progressively.Schizophrenia. Some studies suggest that people who suffer from schizophrenia have larger brain ventricles. In fact, Jordi E. Obiols and Marta Carulla, from the Autonomous University of Barcelona, ​​published an article in the journal Behavioral Psychology in which they suggest that schizophrenic patients show ventricular dilation and cortical decrease, which could be evidence that this disease begins from neurodevelopment.

Therefore, The ventricular system constitutes a fundamental part of our body; As we have seen, its malfunction causes serious alterations in our body.

So, Our ventricular system is a kind of shield that protects us against adversity.. In addition, it does everything possible to maintain the internal balance of our body and to avoid harmful agents.

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