Inside the human brain there are four cavities, called ventricles. The right and left lateral ventricles and the third and fourth ventricles compose the ventricular system. Containing cerebrospinal fluid, the fourth ventricle spans from the obex to the cebebra aqueduct. It has a diamond shape and is located in the upper region of the medulla. The main function of this ventricle is to protect the human brain from trauma and to help form the central canal. This ventricle has a roof and a floor. The roof is composed of the cerebellum and the floor is formed by the rhomboid fossa. Within the floor is the facial colliculus, sulcus limitans and the obex. Much like other portions of the ventricular system inside the brain, the fourth ventricle develops from the area inside the neural tube called the central canal. During gestation, the ventricles form during the first three months of pregnancy. During this time of development, it is possible for circulation to be blocked by overproduction of cerebrospinal fluid, causing hydrocephaluses.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Fourth ventricle