The brain is surrounded by three layers of connective tissue. These three layer nourish and protect the brain. Covering the brain and these three layers of connective tissues is the skull. The skull encases the brain, and is part of the skeletal system. The first layer fo the brain is gray. It is gray because of the billions of neurons. Underneath the gray material is while material. This is made up of bundles of neurons. The mass of the brain is only 1.4 kilograms. Between the middle and inner layer is a watery fluid. This fluid protects the brain from sudden impacts. The inner layer is thicker and tougher then the other two layers, and makes contact with the skull. .
The largest and most noticeable part of the brain is the cerebrum. The cerebrum is lined with deep, wrinkled grooves. The cerebrum is the area where learning, intelligence, and judgement occur. The larger the surface area means an increase in thinking ability. The cerebrum also controls voluntary activities of the body like your attitude, your emotions, and your personality. The cerebrum is divided into halves, a left and a right half. Each half controls a different mental activity. The right half is associated with artistic ability, and the left half is associated with mathematical ability. The right half of the brain controls the left side of the body, and the left half controls the right side of the body. The cerebrum also has four lobes. The frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe. .
Below and to the rear of the cerebrum is the is the second largest part of the brain, the cerebellum. The cerebellum coordinates the movement of your muscles. It also help to maintain balance. This makes your body able to move smoothly. .
Below the cerebellum is the medulla. It connects the brain to the spinal cord. The medulla controls involuntary, actions such as heartbeat, breathing, and blood pressure.
