![]() ![]() The second step takes place with the help of protein transporters located in the epithelium of the choroid. The first step takes place depending on the pressure difference between the plasma and the interstitial fluid of the choroid, so that, in cases of increased pressure of the cerebrospinal fluid, for example in hydrocephalus, the formation of the same is reduced. The formation can be divided into two phases: passive filtration of the fluid from the choroidal capillaries happens in the first stage, followed by active secretion via the choroid epithelium in the second ( 2). These spaces include ependymal cells lining the ventricles of the brain, but the arachnoid membrane, despite being able to secrete peptides and proteins, does not produce liquor. Most of it, about 100 mL, is formed in the choroidal mesh that is located in all four chambers and the rest, approximately 50 mL, is formed in other CNS spaces. It travels through the lateral ventricles (chambers) and through the interventricular openings to the third ventricle, then through the cerebral aqueduct to the fourth, from which it enters the subarachnoid space through lateral and median openings, and is then absorbed through the arachnoid fissures into the veins of the dura. Cerebrospinal Fluid and its FunctionĪccording to the classical theory, the cerebrospinal fluid is formed predominantly within the choroid segment, which is attached to the ventricular wall. The lateral ventricles attach to the middle of the cerebral hemisphere and extend far into the forehead and the occipital region and into the temporal lobe ( 1). Both of these ventricles are connected to the third ventricle by an intercellular (interventricular) opening. Inside both brain hemispheres there is a lateral ventricle, ventriculus lateralis. The lateral walls of the third cerebral ventricle form paired gray nucleus structures - the hill (thalamus) and the suburbs (hypothalamus). This “ water system” anteriorly expands to form the third ventricle, ventriculus tertius. The fourth ventricle continues into the narrow canal of the spinal cord.Īt the anterior end of the bridge, the fourth ventricle continues into a narrow tube that runs into the midbrain and is also called the water system of the midbrain ( 1). The elongated brain and bridge form a rhombic pit, forming the bottom of the fourth brain ventricle, ventriculus quartus, and its roof, like a vault, forms the cerebellum. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |