Question

which statement describes cerebrospinal fluid? multiple choice it maintains a stable ionic concentration in the brain and spinal cord. it reenters the blood stream via the central canal. it is formed by oligodendrocytes. its rate of production is high in children, dropping to lower rates in adults.

Explanation:

Cerebrospinal fluid (CSF) functions to maintain a stable ionic environment (and also provides buoyancy, protection) for the brain and spinal cord. Oligodendrocytes form myelin sheaths, not CSF (CSF is formed by choroid plexus). CSF does not reenter the blood via the central canal (it reabsorbs via arachnoid granulations). The rate of CSF production is relatively constant, not dropping in adults from childhood rates in this context. So the correct statement is about maintaining stable ionic concentration.

Answer:

It maintains a stable ionic concentration in the brain and spinal cord.