When studying the human body, the first steps taken by most students have a lot in common. It does not matter if one is aiming for a professional qualification or whether one is studying the human body out of mere interest. When anatomy and physiology are combined, this is particularly so. Anatomy and physiology are two separate sciences with very different histories. However, for teaching students not studying medicine, they are often combined into a single unit of study. That there are textbooks combining the two sciences illustrates this. There is a lucrative market for such books. Courses in life and health sciences are very numerous. Thus, publishers vie for market share. As a result, the textbooks available have settled on a similar layout and style. Any textbook that bucks the trend will not appeal to a mass market and will not be as commercially successful. As a result, textbooks have converged on a similar approach.
The three overhead projector transparencies (OHTs) mentioned in previous posts represent three common themes in these textbooks. All these textbooks open with an introductory chapter with a title such as Orientation. It is unnecessary to describe in detail here the content of that chapter. Instead, it is important to note how the conceptual framework for the rest of the book gets laid down in this chapter. The Orientation chapter introduces the ideas behind each of the OHTs I mentioned elsewhere.
OHT-1 depicts how the body is divisible into different levels of organisation. The image in the earlier post is interpretable in two ways.
(i) Organisms consist of organs. Organs consist of tissues. Tissues consist of cells. Cells consist of chemical molecules.
Alternatively, one can go in the opposite direction.
(ii) Chemical molecules form cells. Cells form tissues. Tissues form organs. Organs form organisms.
Usually - as in my OHT-1 - a directional arrow is given. However, one may go in either direction. Although a viable option, thinking simultaneously in both directions is not suggested.
The above provides the conceptual framework within which the reader begins to think. Different textbooks offer different versions of what I refer to as OHT-1. In due course, I will post some I have collected over the years.
OHT-1 is a very simplified and incomplete portrayal of what the body is really like. That should be obvious. However, that incompleteness goes uncommented upon and unexplored.
OHT-2 depicts the different physiological systems into which the body is divisible. It would be more accurate to say that it represents how the author or editor of the textbook chooses to divide the body. There are often subtle differences in the naming and sequencing of different body systems. For example, the muscles and bones may be presented as two distinct systems or as a single musculoskeletal system. Again, this provides the conceptual framework within which the reader begins to think.
In the rest of the textbook, each system gets a separate chapter. Details of each system's structures and processes follow. These begin at the organ level and proceed into finer and finer detail.
There is never a chapter at the end of these textbooks that puts everything back together again. (That, in effect, is the Humpty Dumpty Problem.) The physiological systems remain as separate systems. There is never a conceptualising of what the structures and processes mean to the life of the person studying the subject. After all, what they are studying is what they are.
I used to ask students to have in mind this question at all times:
What does this structure or process confirm on me?
Focusing that question on the individual student (the 'me' in the question) was meant to make the subject more pertinent and less abstract.
OHT-3 represents the concept of homeostasis. Homeostasis colours the intellectual framework for understanding much of physiology. As stated in another post, I avoided talking about homeostasis except to say why I was avoiding it. While it is a concept very much ingrained in biological thought, it is not without its critics. That should be acknowledged. However, that is rarely the case. Neither should it be accepted uncritically. That is often the case. The typical description of homeostasis is an uncritical statement of orthodoxy - a statement of a belief held by biologists. Furthermore, it is a belief frequently misunderstood and misrepresented.
