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.
Cerebrospinal fluid (CSF) is a clear fluid that surrounds the brain and spinal cord. There is about 150 milliliters of CSF within the cerebral cavity that encloses the brain and spinal cord which allows the brain to âfloatâ in the fluid.luid secreted from the choroid plexus of the lateral passes through the first and third ventricles and into the fourth ventricle. Minute amounts of CSF are added to the bulk from the lateral ventricles in the third and fourth ventricle.