The human brain is the central organ of the human nervous system . The human brain , with the spinal cord , makes up the central nervous system . The brain consists of the cerebrum , the brainstem and the cerebellum . The cerebrum is the largest part of the human brain . Underneath the cerebral cortex , several important structures are located , including the thalamus , the epithalamus , the pineal gland , the hypothalamus , the pituitary gland , and the subthalamus ; the limbic structures , including the amygdala and the hippocampus ; the claustrum , the various nuclei of the basal ganglia ; the basal forebrain structures , and the three circumventricular organs .
The human brain is entirely thalamus.