Cells need food, water, and oxygen to live and function. So, if an organ is damaged, it means the cells and cell structure in the organ are also damaged. Figure 1.2.2 – Organ Systems of the Human Body: Organs that work together are grouped into organ systems. The Organization and Structure of the Human Body The Organization and Structure of the Human Body The human body is made up of a complex structure of systems that all work together. The liver is the largest internal organ in the human body, which weighs between 1.3 to 1.5 kg. Scientifically, a Cell is the basic unit of life. Refer More: Structure and function of the skin. In the same way, the human body functions a lot like a city, with separate units designated for specific functions, but all working together for a common purpose. See Chapter 10 for changes in body structure and function that occur with aging. Characteristic of the vertebrate form, the human body has an internal skeleton with a backbone, and, as with the mammalian form, it has hair and mammary glands. The organ systems are similar in terms of function and anatomy, starting from amphibians to higher animals. Function, size, and shape may differ. It helps metabolize drugs and other waste from the body through urine. An organism is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life. Cells are very small. Cells, tissues, and organs. Human body, the physical substance of the human organism. A group of cells from a tissue and a group of tissues form an organ.. A group of organs makes up an organ system and a group of organ systems make up the human body.. The skin acquires an area of 19 to 20 square feet on our body surface. Therefore, it is called the largest external organ of the human body. The organism level is the highest level of organization. The different organ systems in the human body include. Cells in a human body are of different types based on their structure and function. Learn more about the composition, form, and physical adaptations of the human body. There are several levels of organization to this structure, with each level more complex than the last. Liver. The basic unit of body structure is the cell. For example, the liver is a part of the digestive system but also plays a prominent role in the excretion system. You need a microscope to see them. Cells have the same basic structure.