All the bones in your body are a part of one main organ system, the skeletal system. It is made up of connective tissue and your bones. It has five main functions. Your skeleton protects and supports your body. It produces blood cells in the bone marrow. Your skeletal system also stores minerals like calcium. They protect your organs, for example the ribs protect your lungs and your skull protects your brain. Another function of the skeletal system is to allow movement by its many joints. The skeletal system is an important organ system, because it has many functions that your body needs for living. .
The muscular system has one job; it provides movement for your body by contracting and relaxing. Most of your muscles move when you want them to, however, some, like your heart, work constantly even when you don't think about it. Each cell releases energy for the muscles to work. The energy is made in the mitochondria of each muscle cell. The cells form a bigger group, like bundles of fibers that work together to move. These muscle fibers are then put into different muscle groups, like your biceps and triceps, which work on moving your arm. The integumentary system is what your skin, hair and nails are. The cells of your skin are working to protect your body from viruses and bacteria. It also helps regulate the temperature of your body. The skin holds your body from falling apart. Skin is also a part of other organ systems too. It interacts with the nervous system to give you information about your surrounding environment, and helps remove waste as a part of you excretory system.
The circulatory system works by the pumping of your heart. It is basically a transportation network for food and oxygen to all of the cells in your body; it also removes waste. Veins carry blood to your heart. Arteries carry the blood away. The veins are covered by connective tissue and the inner walls are covered with epithelial tissue.