The brain is considered a major control center of the body due to its regulation of hormone secretion, body temperature, food and water intake, and sleep. It consists of the cerebral cortex, brainstem, cerebellum, limbic system, midbrain, thalamus, parietal lobes, and hypothalamus. The majority of all sensory pathways pass through and synapse with neurons of the prefrontal cortex. The outermost layer of gray matter of the brain in humans is referred to as the cerebral cortex. Including the amygdala and hippocampus, the limbic system reinforces behaviors important to survival. The hypothalamus is more developed in humans than other animals and controls logic, judgment, and expression of emotion. Composed of three parts, the brainstem provides basic life support functions including roles in the cardiovascular and respiratory systems.