Introduction to Physiology PDF

COURSE: INTRODUCTION TO PHYSIOLOGY Dr. (Mrs.) A. A Bayo-Olugbami  Suggested textbooks and resources ….. Medical Physiology (Guyton and Hall) Review of Medical Physiology, 23th Ed. (W.F. Ganong) Vander’s Human Physiology, 11th Ed. (Widmaier, Raff,...

COURSE: INTRODUCTION TO PHYSIOLOGY Dr. (Mrs.) A. A Bayo-Olugbami  Suggested textbooks and resources ….. Medical Physiology (Guyton and Hall) Review of Medical Physiology, 23th Ed. (W.F. Ganong) Vander’s Human Physiology, 11th Ed. (Widmaier, Raff, Strang)  DEFINITIONS  Physics + Biology = Physiology  The branch of science dealing with the basic functions of living organisms.  Science of “function”  Physiological: “Normal”; not pathological. It means proper ties belonging to normal functions of tissues, organs or body...  It is the scientific study of body functions and mechanisms  Physiology is the science of life. It is the branch of biology that aims to understand the mechanisms of living things, from the basis of cell function at the ionic and molecular level to the integrated behaviour of the whole body and the influence of the external environment.  Physiology is an experimental scientif ic discipline and is of central importance in medicine and related health sciences. It provides a thorough understanding of normal body function, enabling more effective treatment of abnormal or disease states.  Physiology is the study of animal (including human) function and can be investigated at the level of cells, tissues, organ systems and the whole body. The underlying goal is to explain the fundamental mechanisms that operate in a living organism and how they interact. WHY PHYSIOLOGY? Research in physiology helps us to understand how the body works in health and how it responds and adapts to the challenges of everyday life; it also helps us to determine what goes wrong in disease, facilitating the development of new treatments and guidelines for maintaining human and animal health. The emphasis on integrating molecular, cellular, systems and whole body function is what distinguishes physiology from the other life sciences.
 What do physiologists do? All over the world, physiologists are working in universities, in research institutions, in biotechnology companies and in the pharmaceutical industry to advance our understanding of how the body functions. Physiology is an exciting and dynamic discipline that underpins translational and clinical medicine. It also provides the interface between the physical sciences and the life sciences. Physiologists study every aspect of the way human and other animal bodies work. Some physiologists investigate the behavior of individual proteins in single cells. Others are researching the interaction of cells in tissues, organs and systems or study the integration of these systems to control the whole complex organism. They provide the foundation for many biological and clinical sciences, including medicine and veterinary science. They work alongside elite athletes, helping to improve their performance and avoid injury, or they investigate how the body adapts to extreme environmental challenges, such as deep sea diving or prolonged space flight. Physiology is recognized globally.  Physiologists can travel the world to conferences and meetings to present their f indings to other scientists. Some physiologists report scientif ic developments for newspapers, journals and other media, or play an advisory role to Government or charitable organizations. Physiologists also use their skills in the legal arena, engaging in complex issues of patent law, or in education, inspiring and nurturing the next generation. Studying physiology opens doors to employment in all these areas and more. Physiology involves many vital concepts, and homeostasis is one of them. It is the process through which a nearly stable internal environment is maintained in the body so that cellular functions can proceed at maximum efficiency. Every body structure contributes in maintaining the internal environment within a normal range. Changes in the normal range in the body due to infection, or disease lead to symptoms and outward clinical signs. A l t e r a t i o n s i n h o m e o s t a s i s c a n b e e f f e c t o f a d i s e a s e.
Understanding the control of homeostasis is very vital to pinpoint the root cause of any disease. Not all physiologists are found in research laboratories, though. Physiologists also work with patients in hospital clinics, helping with the diagnosis and management of disease.  HISTORY OF PHYSIOLOGY The study of physiology traces its roots back to ancient India and Egypt. As a medical discipline, it goes back at least as far as the time of Hippocrates, the famous “father of medicine” – around 420 BC. Hippocrates coined the theory of the four humors, stating that the body contains four distinct bodily f luids: black bile, phlegm, blood, and yellow bile. Any disturbance in their ratios, as the theory goes, causes ill health. Claudius Galenus (c.130-200 AD), also known as Galen, modif ie d Hippocrates’ theory and was the f irst to use experimentation to derive information about the systems of the body. He is widely referred to as the founder of experimental physiology. It was Jean Fernel (1497-1558), a French physician, who first introduced the term “physiology,” from Ancient Greek, meaning “study of nature, origins.” Another leap forward in physiological knowledge came with the publication of William Harvey’s book titled An Anatomical Dissertation Upon the Movement of the Heart and Blood in Animals in 1628.  HISTORY CONT… Harvey was the first to describe systemic circulation and blood’s journey through the brain and body, propelled by the heart. From here on in, the field of physiology opened up, and progress was made quickly: Joseph Lister, 1858: initially studied coagulation and inf la mmation following injury, he went on to discover and utilize lifesaving antiseptics. Ivan Pavlov, 1891 – conditioned physiological responses in dogs. August Krogh, 1910 – won the Nobel Prize for discovering how blood f low is regulated in capillaries. Andrew Huxley and Alan Hodgkin, 1952 – discovered the ionic mechanism by which nerve impulses are transmitted. Andrew Huxley and Hugh Huxley, 1954 – made advances in the study of muscles with the discovery of sliding filaments in skeletal muscle. Structural and functional hierarchy Physiological terms; Function: Things to do... Mechanism: How to do... Organization of life: Cell is the basic unit of life. Hierarchical organization of life: Cells, tissues, organs, organ, systems and organism  Organization of the Body Structural Hierarchy Atoms: oxygen, carbon, hydrogen Molecules: water, sugar, peptides Macromolecules: proteins, polysaccharides Organelles: compartments within cell that cannot survive in isolation Cells: structural and functional unit of organisms Tissues: organization of cells with a common function Organs: structures composed of at least 2 tissues Organ Systems: organs operating to accomplish a common function Organ-system Cardiovascular System Respiratory System Digestive System Urinary System Reproductive System Musculoskeletal System Nervous System Endocrine System Immune System