Circulatory System: It transports nutrients, water, and oxygen throughout the body. this is important because it circulates nutrients throughout the body.
Respiratory System: involved in exchange of oxygen and carbon dioxide between an organism and the environment. This is important because this system allows you to be able to breathe.
Digestive System: organs responsible for getting food into and out of the body and for making use of food to keep the body healthy, and gets rid of solid waste. This is important because it gets the body the nutrients it needs.
Integumentary System: protects the body from various kinds of damage, such as loss of water or thins that can harm your skin. This is important because it protects the bodys organs from many different types of damages.
Excretory System: responsible for the elimination of wastes. Made up of a combination of certain systems. This is important because i gets rid of waste or at least most of it.
Nervous System: fibers that transmits nerve impulses between parts of the body. This is important because if you didn't have this you would have any nerves and wouldn't survive.
Urinary System: consists of the two kidneys, ureters, the bladder, and the urethra. Each kidney consists of millions of functional units called nephrons. This is important because it gets waste out of the blood.
Skeletal System: The framework of the body, consisting of bones and other connective tissues, which protects and supports the body. This is important because it protect your bodies tissue.
Muscular System: allows the body to move. This is important because it allows people to walk and eat and many other things, without it the body couldn't do a lot of things.
Endocrine System: glands that produce hormones. This is important because the hormones that are released let your organs know what to do.
Immune System: protects the body against harmful diseases. This is important because without it more bacteria would make you sick.
How do they work together? All of these systems work together to make the body work. without these the body wouldn't be able to do the things that it can. If one system didn't complete its job then the other systems would be basically useless.