Cerebrospinal fluid (CSF) is a colorless fluid that surrounds the brain and the spinal cord. It is found between two layers of meninges. Meninges are like sheets that cover the brain and spinal cord.
The three meninges are:
Since pia mater is the layer that clings to the brain covering it and there is a space between the arachnoid mater and the folds of the pia mater. Cerebrospinal fluid fills into this space called subarachnoid space.
At any given point of time, there is 125 milliliters of CSF present in the subarachnoid space. It is produced in the ventricular system of the brain and about 500 milliliters of CSF is generated everyday, which keeps draining out and is constantly replaced. It is derived from blood plasma but is almost nearly protein-free and its electrolyte contents are different from blood plasma.
Functions of Cerebrospinal fluid:
There are several functions of CSF.
The average density of the CSF is equal to the density of the brain and this helps in neutralizing the buoyancy of the brain. If there is an imbalance in the density, CSF would flow away from the place and would cut off blood supply and the nerve cells may permanently be damaged.
CSF provides a fluid buffer or cushioning effect when head is jolted or hit.
CSF adjusts its consistency in the space inside the skull to manipulated blood pressure of the area. It also decreased total intracranial pressure or the pressure inside the skull. These adjustments help prevent brain ischemia (tissue death due to lack of blood).
CSF travels throughout the brain and spinal cord and helps in distribution of substances and electrolytes between cells of the brain. Slight changes in the chemical composition of CSF can result in fever, sickness, dizziness and fainting.
While balancing the electrolytes, CSF also removes waste products coming from the cellular functions of the brain and the lymphatic system of the brain.
Clinically, any changes like pressure, pH levels, electrolyte imbalance, leak of CSF from other outlets, etc can lead to diseases and unwanted conditions. Infections like meningitis can increase volume of CSF and result in headaches and coma.
Most of the illnesses and conditions can be medically or surgically treated. Lumbar puncture is one such treatment to decrease the intracranial pressure. Meningitis is managed clinically along with antibiotics.