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Physiology of Organisms

Subject Summary: Part IA Physiology of Organisms

Physiology deals with how living organisms work. While often concentrating on organs (“how does the heart work?”), it covers life from the molecular level right up to the behaviour of the whole organism. In its applied aspects, physiology deals with the function and malfunction of parts of the animal body with reference to health and disease (areas relating to medicine and veterinary medicine), how to improve crop yield (areas relating to plant sciences) as well as how organisms respond to challenging conditions (areas relating to ecology and evolution). 

We begin with an overview of physiological ideas and problems, as applied to animal physiology. We look at how the basic organ systems such as the nervous, cardiovascular and respiratory systems work, how homeostasis is maintained and how animals respond to environmental challenges. Although mammalian physiology is taught in most detail, this is a comparative physiology course and so we also consider some of the different strategies found in other animals, such as fish and insects.

In the second term we move to plants. How do plants interact with the environment to obtain raw materials, and how these are processed and distributed? Control of growth and development is a major contributor to the survival and propagation of plants at all stages of the life cycle, and we explore the functional links between changes in the world outside and the physiological responses that enable plants to counter or exploit them. The second term concludes with an overview of microbial physiology, including a consideration of how microbes and plants interact. 

The third term takes a more integrative approach, drawing on what has already been learned about plant and animal physiology and considering similarities and differences. We consider the profound importance of body size and scaling in both groups of organisms, exploring aspects such as structure and locomotion, and we discuss the sensory biology of plants and animals. 

Experimental practical classes allow you to explore for yourself what you hear about in lectures, and see how science is actually done. In the animal physiology classes you will, among other things, look at the properties of nerves and muscles, examine the activity of your own heart, discover how different inhaled gas mixtures affect your breathing and even see how much sweat you produce while exercising! In the Plant Sciences practicals you will explore how leaves control gas exchange, how enzymes are regulated and how plants respond to viral infection. 

The Physiology of Organisms course gives a contemporary and integrated understanding of how organisms function. It provides a wider context for the material in the other NST 1A biology courses and represents a strong background for many of our IB well as being of general interest to anyone curious to know how complex biological machines work.

Knowledge of A2-level Biology (or equivalent) is not assumed in this course but is certainly helpful.  Some AS-level knowledge of physics would also be very helpful, but many of our students do not have a physics background. 

Programme Specification: Part IA Physiology of Organisms

This course is taught jointly by the Departments of Plant Sciences, Physiology, Development, & Neuroscience, and Zoology.


  1. to provide a course of basic comparative physiology, introducing students to the principles of normal biological function in a wide range of organisms;
  2. to prepare students for subsequent biological courses that require an understanding of the physiology of organisms;
  3. to show how animals and plants maintain an internal steady state, how they acquire and dispose of nutrients and how they detect and respond to changes in their environments;
  4. to outline the physiology of bacteria and fungi;
  5. to investigate the evolution of physiological mechanisms in vertebrates, and the influence that body size has on physiology;
  6. to develop practical biological skills.

Learning outcomes

At the end of the course students should

  1. have an enhanced knowledge and appreciation of the physiology of organisms;
  2. be able to develop cogent and critical arguments based on the course material;
  3. be able to perform, analyse and report on experiments and observations in physiology;
  4. be able to integrate related topics from separate parts of the course.

Teaching and learning methods

These include:

  • lectures, practical classes, web-based resources;
  • feedback on results achieved in experimental practical classes, in the form of debriefing seminars, web-based material and/or through the marking of practical notebooks (for aim 6 and learning outcome3);
  • College-based supervisions.


Assessment for this course is through

  • a written examination consisting of one practical paper and one theory paper (for aims 1-6 and learning outcomes 1-4);

Courses of Preparation

Essential: None.

Recommended: AS or A Level Biology and/or Physics.

Additional Information

Further information is available on the Course Websites pages.