G5 The Organs of the Body (On Grade)_04

Nervous System

While you have done all the training, you also have to be alert. That’s where your nervous system comes in. The parts of your nervous system include your brain, spine, and nerves. Nerves use your five senses to gather information about the world around you. That information is sent from your nerves to your spinal cord, which is a thick bundle of nerves that connects to your brain. Your spinal cord is sensitive, and is protected by thick, strong bones called vertebrate. Your brain processes the information from your nerves and senses. This allows you to react to what’s happening around you. At your track meet, it will be the nervous system that sends the signals to your muscles that it is time to race! 


The nervous system also senses what your body needs. It tells your heart to beat more quickly and the lungs to breathe more deeply when you exercise. It also senses your body’s temperature. On a long run, your brain tells your skin to release sweat to cool down your body. Your nervous system also senses your body’s condition and ensures you take breaks so you don’t do damage to your muscles or skeleton. It’s like you carry a computer on your shoulders. The brain is the main part of the nervous system, but it does not work alone. It works with the spinal column. The brain sends signals all over your body through the spinal cord. The spinal cord connects to the nerves that gather information.

Digestive and Excretory Systems

In order to compete, your body needs fuel. We get that fuel from the food we eat. Your coach wants you to eat very healthy foods so that your body will be in top form! Your mouth and saliva help to break down the food as you chew. You swallow, and the food travels down the esophagus, a pipe in your throat, to your stomach. Chemicals then break down the food even further in the process called digestion. Your gallbladder released the necessary bile and other chemicals that cause digestion. Digested food, or chyme, is moved into your small intestine first.

The small intestine pulls out important nutrients your body needs and sends them through the bloodstream. The liver then filters the blood before it is carried to all the cells in your body. What’s left of the digested food then makes it into your large intestine. The large intestine absorbs water and moisture from the digested food. The stuff leftover is then converted into a waste product and removed from the body.

The excretory system is your body’s waste management system. Just like the garbage trucks that come to your house and take the trash away. All the food you eat and all the liquid you drink gets used by the body. The digestive system takes out the nutrients your body needs for fuel. Then the left-over materials are excreted, or taken out, of the body by the Excretory System. Your kidneys filter the liquid and your bladder holds liquid waste until it is time to excrete it. The intestines move solid waste out of your body. As you work out, you sweat. Sweat is one way the body gets rid of waste fluids and also allows the body to cool off. If these waste products were not removed, you would become very sick.