Hemorrhoids are classified into two general categories: internal and external. Internal hemorrhoids lie far enough inside the rectum that you can't see or feel them. They don't usually hurt because there are few pain-sensing nerves in the rectum. Bleeding may be the only sign that they are there. Sometimes internal hemorrhoids prolapse, or enlarge and protrude outside the anal sphincter.
Cerebrospinal fluid (CSF) collection is a test to look at the fluid that surrounds the brain and spinal cord. CSF acts as a cushion, protecting the brain and spine from injury. The fluid is normally clear. The test is also used to measure pressure in the spinal fluid. See also: CSF culture.
Potassium. CSF is one of many fluids produced in the human body. This fluid is specific to the central nervous system (the brain, spinal cord). Cerebrospinal fluid (CSF) is the viscous liquid which pads or cushions the brain and spinal cord as well as allowing metabolites and even some cells to disperse in its medium.otassium. CSF is one of many fluids produced in the human body. This fluid is specific to the central nervous system (the brain, spinal cord). Cerebrospinal fluid (CSF) is the viscous liquid which pads or cushions the brain and spinal cord as well as allowing metabolites and even some cells to disperse in its medium.