The brain, a complex structure, allows a human being to perceive and react to her environment, contemplate "the big questions," and experience a myriad of emotions. The brain controls the body and maintains the delicate internal balance needed to sustain life. Although it weighs only 3 lbs., the brain of each individual enables personality, creativity and motion.
Cerebrum
The cerebrum constitutes the largest portion of the brain. Comprised of the two cerebral hemispheres, the basal ganglia and the limbic system, the cerebrum functions to process sensory information and produce output that allows us to think, speak and act. Through the limbic system, the cerebrum also produces the capacity for emotion and memory. The cerebrum contains four lobes: the frontal lobe, parietal lobe, temporal lobe and occipital lobe. Each lobe governs a specific function of sensory perception and action.
Brainstem
The brainstem links the cerebrum to the spinal cord and contains three parts: the midbrain, pons and medulla oblongata. The brainstem contains nerve tracts and bundles of nerve fibers that convey sensory and motor information from the body to the brain and vice versa, and between the cerebrum and cerebellum. The brainstem functions to regulate heart rate, blood pressure, breathing and the wake-sleep cycle, according to an illustrative guide of the central nervous system by Stanford University.
Diencephalon
The diencephalon forms a core of tissue at the center of the cerebrum. The thalamus, hypothalamus, epithalamus and subthalamus regulate and modify sensory input from the body and signals pertaining to movement sent from the cerebrum. The thalamus receives almost all incoming sensory information and relays portions of the information to and between brain structures. Important functions of the hypothalamus include the regulation of the autonomic nervous system, emotions, eating, drinking, body temperature and the wake-sleep cycle, in addition to the production of hormones, according to the National Institutes of Health. The epithalamus links the limbic system to other parts of the brain. Science has yet to determine the precise function of the subthalamus.
Cerebellum
Receiving information from the cerebrum and spinal cord, the cerebellum evaluates the execution of movements made by the body. Signals sent from the cerebrum generate movements of the body. Therefore, the cerebellum evaluates the performance of movements initiated by the cerebrum. If a movement error is detected, the cerebellum will send feedback signals to the cerebrum to correct the errors, smooth movement and coordinate complex movements. The cerebellum also regulates posture and balance, and may play a role in cognition and language processing, according to Medline Plus.
References
- "Principles of Human Anatomy"; G. Tortora and M. Neilsen; 2009
- Stanford University: The Brainstem
- National Institutes of Health: Brain Basics-Know Your Brain
- Medline Plus: Cerebellum Function
