Physiologie

Physiologie, or physiology, is the scientific study of the functions and mechanisms that sustain living organisms. It seeks to understand how organisms perform essential processes such as metabolism, respiration, circulation, neural signaling, movement, digestion, and reproduction, and how they maintain homeostasis in the face of internal and external perturbations. The field spans scales from molecules and cells to organs and entire organisms, and from unicellular life to complex systems.

Major areas of the discipline include cellular and molecular physiology, neurophysiology, cardio- and respiratory physiology, renal and gastrointestinal physiology, endocrinology, and plant physiology. In humans and animals, physiological research emphasizes how organ systems coordinate to preserve stability and adapt to changes, while plant physiology examines photosynthesis, transport, growth, and responses to environmental stress.

Physiologists use experimental observation, quantitative measurement, and theoretical modeling. Techniques range from electrophysiology and imaging to biochemical assays, genetic manipulation, and computational simulations. Comparative physiology compares species to identify general principles and evolutionary adaptations. The insights of physiology underpin medicine, pharmacology, nutrition, exercise science, and bioengineering.

Historical roots lie in ancient medical and philosophical traditions, with later milestones such as William Harvey’s description of circulation and Claude Bernard’s concept of the milieu intérieur, which laid the groundwork for modern experimental physiology and the study of homeostasis.

Physiology provides the foundation for understanding health and disease, guiding diagnosis and therapy, and informing broader domains such as agriculture, ecology, and environmental biology.