Physiology and Health

Abstract

During the past two or three decades, biology has come into its own as an experimental science. There has been a gradual transition from the descriptive to the experimental phase in all of its subdivisions. The foundations of embryology, for example, were laid by the descriptive biologist and contributions are still being made in this area. But more recently the experimental aspects have been developed and tremendous strides have been made by investigators working in this field. In recent years evidence bearing on basic concepts in taxonomy, phylogeny, evolution, etc. has been obtained from genetical, biochemical and serological studies. To understand and appreciate the full implications of 20th Century biology, the teacher and the student must be fully aware of the impact of experimental biology. This has no sharp boundaries for it reaches out toward chemistry, through biochemistry; toward physics, through biophysics; and toward mathematics, through quantitative biologv. Physiology is the study of the functioning of organisms and their component parts. It stands at the crossroads between descriptive biology on the one hand, and chemistry, physics and mathematics on the other. Not all of experimental biology is physiology, but very frequently the techniques which were used first by the physiologist, are now being applied to other areas of biology. Actually, it should not concern us whether we say the man who is studying the distribution of certain enzvmes in a developing embryo is an embryologist, a phvsiologist or a biochemist. The important thing to us as teachers and students of biology is to be in a position to appreciate the general biological significance of such data even if we do not understand the details. Physiology is a broad field with many facets. Roughly we can recognize three major subdivisions: (1) organ system physiology; (2) general physiology; and (3) comparative physiology. Let us briefly consider some of the most obvious implications of an appreciation of each of these areas. Organ system physiology. It is difficult to select an appropriate term to describe this area. Perhaps Mammalian Physiology would be better, but rather than labor the problem of what to call it, let us briefly describe what we mean. This is the kind of physiology with which all of us are familiar. It involves a study of how the various organ systems function, as for example: what happens to food when it passes down the alimentary canal; how does the heart function and what changes occur in the blood as it circulates; how do we breathe; what mechanisms coordinate these systems into a whole; and so on. Most high school and college biology texts have at least some discussion of this aspect of physiology, and with the recent emphasis on human biology, further impetus has been given to the study of human physiology. In the broadest meanings of the terms, medicine is applied physiology. A doctor must first understand the normal functioning of the body before he can determine the extent and possible causes of abnormal functioning (diseases). The standard tools of every doctor-the thermometer, the stethoscope, the sphygmomanometer-are instruments for testing the basic functioning of the bodv. A knowledge of human physiology, then, is a necessary requisite for evaluating and exercising good health practices. With so manv articles in the press concerning health and medicine, a person must understand at least the basic principles of human physiology in order to read intelligently. Furthermore, since physiology is an experimental science, an acquaintance with its methods should contribute to an appreciation of scientific methods. This is necessary in order to evaluate the many news releases pertaining to health and medicine. General Physiology-The two remaining broad areas of physiology are, for the most part, completely overlooked in the training of most teachers and students of biology. This