Human biology is the study of the structures, functions, and processes of the human body. The human body is made up of different organs, tissues, cells, and systems that work together to maintain homeostasis, or a stable internal environment. Some of the major systems in the human body include the nervous system, cardiovascular system, respiratory system, digestive system, and immune system. The study of human biology helps us to understand how these systems work, how they can be affected by disease or injury, and how we can use this knowledge to improve human health and well-being.