physiology

noun

phys·​i·​ol·​o·​gy ˌfi-zē-ˈä-lə-jē How to pronounce physiology (audio)
1
: a branch of biology that deals with the functions and activities of life or of living matter (such as organs, tissues, or cells) and of the physical and chemical phenomena involved compare anatomy
2
: the organic processes and phenomena of an organism or any of its parts or of a particular bodily process

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Physiology Has Latin Roots

The Latin root physio- generally means "physical", so human physiology deals with just about everything that keeps us alive and working, and other physiology specialties do the same for other animals and for plants. To do anything serious in the field of health, you've obviously got to know how the body's organs and cells function normally. Physiology used to be considered separately from anatomy, which focuses on the body's structures; however, it's now known that structure and function can't easily be separated in a scientific way, so "anatomy and physiology" are often spoken of in the same breath.

Examples of physiology in a Sentence

She took a course in anatomy and physiology. the physiology of diseased plants
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Knowing how the brain moves in spaceflight and subsequently recovers allows researchers to understand the effects of microgravity on human physiology. Rachael Seidler, The Conversation, 11 Feb. 2026 Much of the research guiding treatments, dosages and even medical textbooks continues to be grounded in male physiology. Michelle Kaufman, Baltimore Sun, 9 Feb. 2026 Arutyunyan, who began coaching in his native Armenia, was first trained in the Soviet style that relied on biomechanics and physiology to unlock efficient jumping techniques. Los Angeles Times, 9 Feb. 2026 Radoje Milić is head of exercise physiology at the University of Ljubljana, responsible for testing the majority of Slovenia’s top athletes. Jacob Whitehead, New York Times, 9 Feb. 2026 See All Example Sentences for physiology

Word History

Etymology

Latin physiologia natural science, from Greek, from physi- + -logia -logy

First Known Use

1615, in the meaning defined at sense 1

Time Traveler
The first known use of physiology was in 1615

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Cite this Entry

“Physiology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/physiology. Accessed 22 Feb. 2026.

Kids Definition

physiology

noun
phys·​i·​ol·​o·​gy ˌfiz-ē-ˈäl-ə-jē How to pronounce physiology (audio)
1
: a branch of biology dealing with the processes and activities by which life is carried on and which are special features of the functioning of living things, tissues, and cells
2
: the life processes and activities of a living thing or any of its parts or of a particular bodily process

Medical Definition

physiology

noun
phys·​i·​ol·​o·​gy ˌfiz-ē-ˈäl-ə-jē How to pronounce physiology (audio)
plural physiologies
1
: a branch of biology that deals with the functions and activities of life or of living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved compare anatomy sense 1, morphology sense 1
2
: the organic processes and phenomena of an organism or any of its parts or of a particular bodily process
the physiology of the thyroid gland
3
: a treatise on physiology

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