The human brain is a complex organ and is responsible for relaying information to the other parts of the body. For example, the brain is involved in memory, thinking, voluntary and involuntary movements. Multiple components make up the human brain, starting as small as the molecular level with the electrical synapses that transmit signals to different areas of the body. On the larger anatomical level, the human brain is made up of three major components: the cerebrum, cerebellum and brain stem.
Cerebrum
The cerebrum is the largest part of the brain, about 85 percent of the total weight, according to the National Institute on Aging. The cerebrum is divided into two hemispheres--the left and right hemispheres--that communicate to each other via the corpus callosum; when the corpus callosum is severed, such as with split brain surgery, each hemisphere acts on its own. The Centre for Neuro Skills states that each hemisphere contains four lobes: the frontal lobe, parietal lobe, occipital lobe and temporal lobe. The frontal lobe, located at the forehead, is responsible for emotions, consciousness and word associations. The parietal lobe, located behind the frontal lobe toward the top of the head, controls visual attention, touch perception and voluntary movements. Located at the back of the head toward the top, the occipital lobe is the region responsible for vision. The temporal lobe, located near the ears, deals with hearing and memory acquisition.
Cerebellum
The National Institute on Aging states that the cerebellum is the second largest part of the brain, taking up slightly more than 10 percent of the brain's weight. Located in the back of the brain, below the occipital lobe, the cerebellum controls balance and coordination.
Brain Stem
The last major component of the human brain, the National Institute on Aging states the brain stem is located at the base of the brain, and connects the brain to the spinal cord. While it is the smallest part of the brain, the brain stem controls essential bodily functions, such as breathing, heart rate and blood pressure. If damage occurs to the brain stem, the effects can be fatal or put the patient into a vegetative state.
