Ventricles - Nervous System

Ventricles

The CNS contains fluid-filled cavities, called ventricles, which are quite small in some areas and large in others (figure 8.35). Each cerebral hemisphere contains a relatively large cavity called the lateral ventricle. The third ventricle is a smaller, midline cavity located in the center of the diencephalon between the two halves of the thalamus and connected by foramina (holes) to the lateral ventricles. The fourth ventricle is located at the base of the cerebellum and connected to the third ventricle by a narrow canal, called the cerebral aqueduct. The fourth ventricle is continuous with the central canal of the spinal cord. The fourth ventricle also opens into the subarachnoid space through foramina in its walls and roof.