The choroid plexus (CP) is a type of filtering system for the brain. It manufactures a type of liquid called cerebrospinal fluid (CSF). The CP eliminates foreign materials, extra neurotransmitters, and metabolic waste from the cerebrospinal fluid. It nourishes and protects the extracellular surroundings of the brain so that the brain and spinal cord can function efficiently. The choroid plexus is located within a region of the brain that does not affect a person's thinking or personality.
Choroid epithelial cells separate the ventricles, which hold the cererospinal fluid in the brain, from the plentiful capillaries that the CP consists of. When fluid flows from blood through the choroid epithelial cells, cerebrospinal fluid is produced. In addition to the ventricle area, the fluid is located inside of the sub-arachnoid, the area around the spinal cord and the brain.
The choroid plexus are found in four parts of the brain, in specific areas within the brain's ventricular system. They are made of cuboidal epithelial cells that encircle movable connective tissue within the brain and the numerous capillaries. These cells make up a continuous layer lining the ventricles. The way this layer is constructed allows it to act as a barrier between the blood and the cerebrospinal fluid, stopping most foreign materials in the blood from entering the CSF.
The CP accomplishes this by collapsing and folding, and becoming numerous villi. Villi are hair-like extensions surrounding every capillary. The CP then makes leaf-like developments that enter into the ventricles. The exterior area of the CP is then significantly increased with villi as well as microvilli.
At this time, CSF is produced. Plasma is sifted and transported from the blood throughout the epithelial cells. In addition, chloride, bicarbonate ions, and sodium are also transported through the CP epithelial cells and then enter into the ventricles. When this happens, water is transported.
There are times when cysts, referred to as a choroid plexus cysts, are discovered within the interior of the choroid plexus. Although these cysts are sometimes formed either on one side of the CP or on both, they have not been known to be harmful. The cysts can also vary in size, but they are not known to result in cancer, mental problems, or learning disabilities.