Fissure filling is a treatment that improves the apparent clarity of a gemstone by removing air and replacing it with a substance that has a refractive index similar to the host material. Many different substances may be used to fill fissures: oils, resins, waxes, glass, and various polymers, to name a few.
Cerebral autoregulation is a process in mammals, which aims to maintain adequate and stable cerebral blood flow.hile most systems of the body show some degree of autoregulation, the brain is very sensitive to over-and underperfusion. Cerebral autoregulation plays an important role in maintaining an appropriate blood flow to that region.
The hindbrain contains several structures that regulate autonomic functions, which are essential to survival and not under our conscious control. The brainstem, at the top of the spinal cord, controls breathing, the beating of the heart, and the diameter of blood vessels.he preponderance of the cerebral cortex (which, with its supporting structures, makes up approximately 80 percent of the brain's total volume) is actually a recent development in the course of evolution.