Made of nerves, sense organs, brain, and spinal cord. Nervous System Made of nerves, sense organs, brain, and spinal cord. Reflexes are fast because you don’t need to think about them. The nervous system senses the environment and controls your reaction to it. This Photo by Unknown Author is licensed under CC BY-SA

Body organization Cells make tissues, tissues join together to make organs, organs join together to form organ systems.

Circulatory System Moves blood through the body. Gets rid of carbon dioxide and carries oxygen to the cells.

Respiratory System Gets oxygen to your cells, releases carbon dioxide. Made up of trachea, lungs, and nose. Trachea connexts mouth/nose to lungs. IF you hold your breath, carbon dioxide builds up in your blood. You have two lungs.

Digestive System The small intestine is where food is absorbed by your blood. Large intestine is where excess water is removed and food waste is stored. Your digestive system breaks down food into small particles. Your teeth chomp it up, your saliva softens it, stomach mixes it up with acid, Small intestine absorbs it and sends it to your body cells. Your cells turn the food into energy.

Excretory System Excretory system removes wastes from your body Kidneys clean wastes from our blood. You have two kidneys. Your skin releases wastes through its sweat glands.

Muscles and Skeleton Both the muscular system and skeletal system are necessary to help you move. Muscles work in pairs because one contracts while the other relaxes. Some muscles work without you thinking about them. Your muscles in the esophagus squeeze food down to your stomach.