What does a spinal tap procedure primarily collect?

A spinal tap, also known as a lumbar puncture, is specifically designed to collect cerebrospinal fluid (CSF). This procedure involves inserting a needle into the lower part of the spinal column, typically between the vertebrae in the lumbar region, to withdraw fluid that surrounds the brain and spinal cord. The collection of CSF serves several important diagnostic purposes, such as evaluating for infections, bleeding, or diseases affecting the central nervous system, like multiple sclerosis or certain cancers.

Cerebrospinal fluid is crucial for providing information about the health of the brain and spine. Unlike the other options listed, a spinal tap does not involve the collection of blood, urine, or serum. Blood from the brain is not a standard collection in this procedure, urine samples are obtained through different means, and serum typically refers to a component of blood obtained through venipuncture, not from the spine. Therefore, the collection of cerebrospinal fluid is the primary aim of a spinal tap procedure.