Reader Comments

Focus ZX1

by princy william (2019-02-13)

Human brain is well Focus ZX1 Review encapsulated within a thick, bony skull. The choroid plexus secretes the cerebrospinal fluid (CSF) which surrounds the brain. The fluid passes down through the four ventricles with the help of subarachnoid space and finally enters the cerebral veins through the arachnoid villi. Brain lacks lymphatic system so CSF acts as a partial substitute. Dura mater is a tough, protective connective tissue firmly attached to the skull and includes the subarachnoid space filled with the CSF, arteries and web-like connective tissue known as archanoid mater. The pia mater is a very delicate and permeable membrane composed of collagen, elastin and fibroblasts that rests on the floor of subarachnoid space and allows diffusion between CSF and the interstitial fluid of brain tissue. The pia mater is also interrupted by astrocyte processes. The dura mater, arachnoid mater and the pia mater are collectively known as meninges.The brain and CSF are separated from each other by the blood-cerebrospinal fluid barrier and the blood-brain barrier (BBB) which protects brain from undesirable blood substances. These barriers are permeable to water, oxygen, carbon dioxide, small lipid soluble molecules, electrolytes and certain essential amino acids. The barriers are formed by the combined action of endothelial cells lining the capillary walls and glial cells (astrocytes) that wrap the capillaries with fibers. The brain has a distinct chemical composition for example, structural lipid accounts for 50% dry weight of brain, a feature which is in contrast with other fatty tissues of the body that are made up of triglycerides and free fatty acids. The blood brain barrier forms a protective chemical environment through which neurotransmitters can easily participate in nerve impulse conduction.