Question

Some fluid continues down the central canal of the spinal cord, but most of it circulates into the subarachnoid space by passing through three tiny openings in the walls of the _____________.

a. Ventricles
b. Meninges
c. Arachnoid granulations
d. Foramina

Answer 1

Most cerebrospinal fluid circulates into the subarachnoid space through the median aperture and lateral apertures in the fourth ventricle walls.

Step-by-step explanation:

Circulation of Cerebrospinal Fluid

Most of the cerebrospinal fluid (CSF) circulates into the subarachnoid space by passing through three tiny openings in the walls of the fourth ventricle. These openings are known as the single median aperture and the pair of lateral apertures. The CSF is produced within the ventricles by the choroid plexus and is a clear solution consisting of water, small molecules, and electrolytes. It provides important functions such as removing metabolic wastes and acting as a liquid cushion for the brain and spinal cord. Eventually, the CSF is reabsorbed into the blood at the arachnoid granulations, completing the circulation process.

The fluid circulates into the subarachnoid space by passing through three tiny openings in the walls of the ventricles. These openings are known as the median and lateral apertures. The ventricles are part of the ventricular system, which includes the lateral ventricles, third ventricle, cerebral aqueduct, and fourth ventricle.