The Human Body Lesson The Central Nervous System(CNS) consists of your brain and spinal cord. Billions of brain cells called neurons send electrical signals from your brain out to your body. These signals can travel up to 220 miles per hour! The space between neurons is called a synapse. The Peripheral Nervous System are nerves that originate in, or are linked to the Central Nervous System. These nerves branch out from the spinal cord, to the rest of the body, controlling it’s movement. This is a real human whose nervous system has been removed. The peripheral system are the branches coming from the spinal cord. The Autonomic Nervous System controls the automatic functions of the body. Some of these functions include heart rate, breathing, digestion, sweating, saliva production. It also plays an important role in our “fight or flight” reflex whenever emergencies arise. Ummm Not sure… Maybe Fight? Probably Flight The three parts of the nervous system are the Central, Peripheral, and Autonomic Nervous systems. The nervous system is your body’s communication system. This system is made of the brain, spinal cord, and nerves. The left side of the brain controls the right side of the body. The right side of the brain controls the left side of the body. Try not to think about this image when you lay down to sleep tonight…peering out from under your bed…..or the closet… Brain- master control center. Receives info from body and decides what to do. Spinal cord Main route of communications. Nerves are branching wires that connect all parts of the body. Sensory nerves messengers that carry signals to the brain and spinal cord from the body. They let you feel touch, heat, cold, pain, etc. Motor nerves carry orders from the brain to muscles. His sensory nerves are telling him this hurts….a lot. Mario using his motor nerves to do some parkour. The nervous system allows us to respond to our environment. A stimulus is something to which you react. A sight, sound, smell, touch. A response is how we react to the stimulus. A reflex is when you react without even thinking. The Cerebrum is the largest part of the brain. It makes up 85% of the brain’s total weight. It is divided into two halves called hemispheres. The front of the Cerebrum is responsible for thinking. The Cerebellum is responsible for keeping you balanced and coordinated. The Brain Stem (Medulla)connects the brain to the spinal cord. It controls automatic functions such as breathing, digestion, circulation.