b'Nervous SystemChapter hapterThe nervous system is very complex and delicate.The brain is the centre of the nervous system and regulatesall body functions, including the respiratory and circulatory systems. The brain receives and transmits information through a complex network of nerves.The spinal cord is a large bundle of nerves that extend fromthe brain through the backbone to every part of the human body.Nerves transmit messages as electrical impulses from one area of the body to another.Sensory nerves conduct impulses from the body to the brain such as what you may smell, feel, taste, touch and hear.Motor nerves conduct impulses from the brain to themuscles allowing you to control muscle movement. Integrated nervous function of the brain involves conscious state, emotions and language.Autonomic nerves control functions that do not requireconscious thought, such as breathing, involuntary muscles such as the heart, diaphragm and intestines.Sending and Receiving MessagesHow do my nerves help me if I am in danger?If you see an angry bull charging toward you, electrical signals quickly transmit from your eyes to your brain. The sensory nerve cells within your brain receive this information, check it out and then quickly decide what to do. An urgent message stating dangerous charging bull is flashed to the motor nerve cells in your arms, legs and other muscles. The muscles are alerted to this message and you are immediately put into fast running mode.The Breathing BrainThe brain needs enormous amounts of oxygen to survive. It can be severely damaged in only a few minutes if the oxygen supply is cut off. Oxygen is brought to the brain by arteries that carry oxygen rich blood. Even though the brain is quite small, it requires one fifth of all the bodys blood supply.How Your Body Works 29How Your Body Works29'