What are 4 of the organ systems in the human body Describe each system and its function in a healthy body?

Four key organ systems in the human body are the circulatory, respiratory, digestive, and nervous systems. The circulatory system, consisting of the heart and blood vessels, transports oxygen, nutrients, and hormones throughout the body while removing waste products. The respiratory system, including the lungs and airways, facilitates the exchange of oxygen and carbon dioxide, ensuring that the body receives the oxygen it needs for cellular functions. The digestive system, composed of organs like the stomach and intestines, breaks down food into nutrients that provide energy and support growth, while the nervous system, made up of the brain, spinal cord, and nerves, coordinates bodily functions and responses to external stimuli, maintaining homeostasis.