Human anatomy is the study of the body’s parts and how they work. Some of these structures are so small that you need a microscope to see them and figure out what they are. Other bigger structures are easy to see, touch, measure, and weigh. The Greek root of the word “anatomy” means “to cut apart.” At first, people studied human anatomy by looking at the outside of the body and at the wounds of soldiers and other people who had been hurt. Later, doctors were given permission to cut into dead bodies to learn more. When a body is dissected, its parts are cut apart so that the parts’ physical properties and how they connect to each other can be studied. Pathology labs and anatomy classes in medical schools still use dissection. Several imaging techniques, on the other hand, have been made so that structures of the body can be seen. With these techniques, doctors can see things inside a living body, like a cancerous tumor or a broken bone.
Like most scientific fields, anatomy has different areas of focus. Gross anatomy is the study of the body’s larger parts that can be seen without a magnifying glass. Since “macro” means “big,” “macroscopic anatomy” is another name for “gross anatomy.” Micro-, on the other hand, means “small,” and microscopic anatomy is the study of structures that can only be seen with a microscope or other magnifying devices. The study of cells, called cytology, and the study of tissues, called histology, are both part of microscopic anatomy. As microscope technology has improved, anatomists have been able to look at structures in the body that are smaller and smaller, from slices of big structures like the heart to the three-dimensional structures of big molecules in the body.
Anatomists study the structures of the body from two main points of view: regional and systemic. Regional anatomy is the study of how all the components of a certain part of the body, like the abdomen, work together. Regional anatomy helps us understand how different parts of the body work together, like how muscles, nerves, blood vessels, and other parts serve a certain part of the body. Systemic anatomy, on the other hand, is the study of the parts that make up a body system, which is a group of parts that work together to do a specific job. For instance, a systemic anatomical study of the muscular system would look at all of the body’s skeletal muscles.
Physiology is about how things work, while anatomy is about how they are put together. Human physiology is the scientific study of how the chemistry and physics of the body’s parts and how they work together to keep life going. Homeostasis is an important part of the study of physiology. It is the state that living things are in when their internal conditions stay the same. Observing with the naked eye and with microscopes, as well as manipulating and measuring, are all part of the study of physiology. But most of the progress in physiology today comes from carefully planned lab experiments that show how the many structures and chemicals that make up the human body work.
Physiologists usually focus on a certain area of physiology, just like anatomists do. Neurophysiology, for example, is the study of how the brain, spinal cord, and nerves work together to do things as complicated and different as seeing, moving, and thinking. Physiologists may work at both at the organ and at the molecular level. For example, they may look at what different parts of the brain do (such as exploring how an electrochemical signal travels along nerves).
Form and function are linked in all living things. For example, the thin flap of your eyelid can snap down and move almost instantly back up to let you see again. This is how it gets rid of dust. The eyelid can move and close quickly because the nerves and muscles that control it are set up and work in a certain way. On a smaller scale, the way these nerves and muscles work depends on how certain molecules and ions interact with each other. Even the shape of molecules in three dimensions is important to how they work.
The study of anatomy and physiology will make more sense if you keep making connections between the way structures look and how they work. In fact, it can be frustrating to try to study anatomy without knowing how a body structure works. Imagine trying to understand how the bones of the human hand are arranged in a unique way if you didn’t know what the hand is for. Since you know how the human hand uses tools like pens and cell phones, you can appreciate how the thumb is set up differently from the other four fingers. This gives your hand a structure that lets you pinch and grip things and type text messages.
Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Cruz, D. H., … DeSaix, P. (2013). Anatomy and Physiology. Houston, Texas: OpenStax. Retrieved from https://openstax.org/details/books/anatomy-and-physiology