Cerebral aqueduct divides midbrain into anterior and posterior aspects. The part of midbrain which is located posterior to the cerebral aqueduct is called tectum. The part of midbrain which is located anterior to the cerebral aqueduct is called tegmentum. Tectum consists of two round swellings called superior and inferior colliculi. Since superior and inferior colliculi receive visual and auditory fibers respectively and relay them to the thalamus therefore we can conclude that the function of tectum is to control the visual and auditory reflexes. Tegmentum consists of three areas; red nucleus, substantia niagra and periaqueductal grey area. They are involved in the control and relay of sensorimotor information, co-ordination of movement and reward and suppression of pain respectively.