The cavities and hollow spaces within the brain are called which of the following?

The correct choice is ventricles because they specifically refer to the interconnected cavities and hollow spaces within the brain that are filled with cerebrospinal fluid (CSF). These structures play a vital role in cushioning the brain, maintaining intracranial pressure, and serving as a conduit for nutrient distribution and waste removal. The four primary ventricles in the brain are the lateral ventricles, the third ventricle, and the fourth ventricle.

The subdural space is a potential space between the dura mater and the arachnoid mater that can become filled with blood or fluid in certain pathological conditions but does not refer to the hollow spaces within the brain itself. The hypothalamus is a critical part of the brain that helps regulate various bodily functions, including temperature regulation, hunger, and thirst, but it is not a cavity. The subarachnoid space is the area between the arachnoid mater and the pia mater that contains cerebrospinal fluid, but it is not classified as a cavity or hollow space within the brain like the ventricles are.