There are 11 major organ systems in the human body that work together to maintain homeostasis. The document proceeds to provide brief descriptions of several key organ systems, including the integumentary system, cardiovascular system, respiratory system, digestive system, urinary system, nervous system, endocrine system, lymphatic system, muscular system, skeletal system, and reproductive system. Each system has specific structures and functions that work interdependently to keep the human body functioning properly.