Anatomy and physiology are interrelated disciplines. Anatomy is an ancient science. In fact, the term anatomy is derived from the Greek words ana temnein, which mean "to cut apart." Anatomy is the study of the structure and form of an organism. Anatomists study the structures of organs. To do this, they most often dissect an organism. When studying structures of the body, anatomists can use either macroscopic or microscopic methods. Macroscopic anatomy, or gross anatomy, allows scientists to describe large structures, organs, and organ systems with the unaided eye. Dissecting a human lung or heart to observe its muscle and other tissues is an example of gross anatomy. Microscopic anatomy, commonly referred to as histology, is the study of an organism's tissue structure under a microscope. Anatomists also collect information through the careful observation of intact organisms. For example, imaging tools such as magnetic resonance imaging (MRI) provide anatomical information.
Physiology is the study of the function of these organs and organ systems under both normal and altered conditions. Physiologists aim to understand how organisms carry out the functions they need to live, including how they eat, breathe, move, reproduce, and survive in their environments. Physiologists also study how organisms adapt these functions to survive when the environment changes. They use observation and experimentation to determine the function of organs. To do this, they must have an understanding of an organ's anatomy, or form, in order to draw conclusions about its function. One method that physiologists use includes the process of auscultation, which is the process of listening to sounds that the body produces, usually with the aid of a stethoscope.