Fysiologin

Fysiologin, or physiology, is the natural science that studies how living organisms and their parts function. It seeks to explain the processes that sustain life, from molecular activities inside cells to the operation of organ systems, and how these processes interact to maintain homeostasis.

The discipline spans multiple levels of organization and integrates with anatomy, biochemistry, biophysics, and molecular biology. Major branches include general physiology and system-oriented subfields such as neurophysiology, cardiovascular physiology, respiratory physiology, renal physiology, gastrointestinal physiology, endocrine physiology, and reproductive physiology, as well as musculoskeletal and immune physiology. Subareas like exercise physiology and environmental physiology address how activity and external conditions affect function.

Methods rely on experimental and observational studies in humans and animal models, in vitro experiments, electrophysiology, imaging (for example, MRI or PET), biochemistry, molecular biology, and computational modeling to test hypotheses about how systems work.

Applications of fysiologin are broad: informing medical practice and pharmacology, guiding clinical research, shaping rehabilitation and sports science, and enabling biotech innovations and public health strategies.

Historically, the field developed from anatomical and clinical observation to a rigorous experimental science. Claude Bernard is often called the father of modern physiology for introducing the controlled experiment concept, while earlier work on circulation by William Harvey and others laid foundational insights.

Fysiologin remains central to medicine, biology, and allied health disciplines, and continues to evolve with advances in imaging, genomics, and systems biology.