The brain is divided into forebrain, midbrain, and hindbrain. The forebrain consists of cerebrum and diencephalon. Diencephalon encloses the third ventricle. It is made up of lateral walls known as the thalamus, the floor which is known as the hypothalamus and the roof is epithalamus. Thalamus acts as a relay center. It connects the cerebellum with the cerebrum. Hypothalamus forms a stalk to which pituitary gland is attached. Epithalamus forms a stalk to which pineal gland is attached.