physiologies

Physiologies is the plural form used to refer to the various physiological systems across living organisms, as well as to the science that studies them. Physiology aims to understand how organisms function at multiple levels—from molecular and cellular processes to tissues, organs, and whole-body systems. It covers the mechanisms underlying energy production, growth, response to stimuli, and adaptation to changing environments.

Key areas include metabolism, respiration, circulation, neural and hormonal signaling, sensory transduction, movement, digestion, osmoregulation, and reproduction. A central concept in physiology is homeostasis, the regulation of internal conditions through feedback mechanisms that maintain stability despite external variation. Organismal physiology often integrates these processes to explain how whole organisms function in their ecological contexts.

Subfields span cellular physiology, which focuses on the processes inside cells; organ-system physiology, such as cardiovascular, respiratory, neurophysiological, renal, and digestive physiology; and plant physiology, which studies photosynthesis, transpiration, growth, and stress responses. Developmental physiology, exercise physiology, reproductive physiology, and comparative physiology (the study of differences and similarities across species) are also important, as is pathophysiology, which examines how physiological processes go awry in disease.

Methodologically, physiology relies on experimental studies in vivo and in vitro, imaging and electrophysiology, molecular and cellular techniques, and computational modeling. It often uses model organisms and crosses disciplinary boundaries with biochemistry, genetics, and neuroscience. Applications of physiological knowledge span medicine and clinical practice, pharmacology, sports science, agriculture, and ecology, reflecting physiology’s broad relevance to health, performance, and understanding life itself.

Physiology derives from Greek roots meaning the study of nature. The term physiology is commonly used as a mass noun, while physiologies can denote the distinct physiologies of different organisms or systems.