To understand biological systems most students will have studied the cell, its specialist components, and their functions. However, during the study of such a microcosm, it is easy to lose sight of the bigger picture: the major function of life is to survive and to hopefully propagate. The only way for an organism to survive is for cells to maintain the conditions of life i.e., homeostasis. This is perhaps the most important concept to consider in your study of biological systems as it predicts the behaviour of systems entirely.
In your studies of physiology, it is therefore important to understand three things about all the major systems you study. If you cannot explain these in a basic sense and you have studied the systems, it is likely you have become too consumed in the details:
- What does the system do?
- Why does it do this?
- How does the system do it?
By asking such questions and ignoring everything else (for now), you are taking a critical approach to the system — all you want to know is what the system does, why this is important, and how it meets this objective. Because of this process, you will be able to easily apply the universal knowledge to comparable systems in different organisms. If you have sat GAMSAT before, you will know how important it is to be able to apply existing knowledge in new contexts.
For example, consider the respiratory system:
- It provides important substrate to the body in the form of O2, whilst also removing CO2 waste It also has minor roles in temperature regulation and some endocrine function
- It operates to ensure ATP energy can be produced through oxidation, and damaging waste products do not accumulate i.e., the respiratory system controls blood O2 and CO2 concentrations to control systemic pH
- The system manages O2 and CO2 concentrations through dynamic pressure changes based upon changes in volume controlled by contraction and relaxation of muscles surrounding the thoracic cage. Inside the bellows (lungs), exchange occurs down concentration gradients (passive diffusion) between the lungs and blood stream. Without a moving stream of blood, the system is redundant.
Once you understand the basics, it is time to increase the level of detail. In this case, you may choose to learn more about gas transport, or choose to learn the names of the muscles responsible for inspiration and expiration. Importantly, you now have no doubt in your mind as to the key questions examined.