General Concepts in Anatomy
The study of human body structure is referred to anatomy while the study of the functions of these structures is referred to physiology (Moreau, Stockslager, Cheli & Haworth, 2002). Before understanding the structure and function of the human body, it is critical to first look at a few fundamental aspects.
The first thing to consider is how the smallest structures are organized into bigger structures. While considering the structures, it is convenient to understand the fundamental levels of the smallest parts to the biggest structures. These levels include:
- Chemical level – This is the lowest level and is made up of subatomic particles, atoms and molecules. Here, subatomic particles come together to form atoms, while atoms form bonds to form molecules such as water and oxygen.
- Cellular level – At this level, several molecules come together to form matter in terms of fluids, organelles, and other components that make up a human cell (Moreau, 2002). A cell in the fundamental unit of life and every living organism has at least a cell or a cellular structure.
- Tissue level – Tissues are made up of several cells that are similar in nature and function. An example of a tissue is the connective tissue.
- Organ level – Organs are made up of several tissues that come together to form a unit that performs one or more functions. Examples of organs include the heart, bladder and liver.
- Organ system level – This is made up of a few organs that work in collaboration to perform various functions related to the body system.
- Organism level – This is the highest level and it involves several organ systems that work together in collaboration to conduct the various functions in an organism (Moreau, 2002).
A critical element in understanding the structure and function of the human body is the cell and its function. As mentioned above, a cell is the smallest independent unit of an organism and most of the functions in the human body are performed by independent cells. Whereas cells can assume different functions, they all have the common role of producing energy, reproduction, as well as cell maintenance. This makes cells critical in maintaining the physiology of the human body, including repair and growth. For instance, cells perform the function of growing new tissues after an injury and they are also necessary for sending messages to the brain and to the central nervous system. Cells are also the building blocks of the larger units including the tissues, organs, organ systems and a whole organism. Since cells are the basic unit of life, without them, life will simply not exist (Moreau, 2002).
Homeostasis is another relevant element in the structure and function of living organisms. Homeostasis is a process involving two or more body functions that work closely to maintain the right environment for cells to perform their functions (Moreau, 2002). For cells to continue performing their function as the independent units of life, they rely on the movement of molecules and chemicals such as oxygen in and out of the cell. The movement of these molecules is made possible through homeostasis. Homeostasis helps to maintain a balance between how the cell and entire organism uses and acquires energy. In addition, homeostasis is critical in maintaining a balance and stability in terms of body temperature, glucose levels, and fluid volume necessary for cell function. At the organ system and organism levels, homeostasis helps to regulate various things including the blood pressure, breathing, and other mechanisms for proper growth and function.