What is the difference between internal and external systems of the human body?

Internal systems of the human body refer to structures and processes that occur within the body, such as the circulatory, respiratory, and digestive systems, which work to maintain homeostasis and support life. External systems, on the other hand, involve interactions between the body and the outside environment, including the integumentary system (skin, hair, nails) and sensory organs that help in perceiving external stimuli. While internal systems focus on internal functions crucial for survival, external systems facilitate interaction and protection from the environment. Together, they ensure the overall health and functionality of the organism.