The material for this web page comes from Chapter 1 of your textbook. To get to any particular topic within this chapter, click on the appropriate term in the image below!
When describing the human body, you can describe the parts of it and how they physically fit together, or, you can describe how those parts function. The basic layout of the body is its anatomy, while the way the body parts work is its physiology. It is easier to learn about anatomy when we are in lab and can examine all the "parts" of the body, so that is the main emphasis of the laboratory section of this course. Learning how things work is the physiology portion of this course; it usually requires many hours of study time to work through the processes of how the body functions, and then to let this new information gel in your mind so that it makes sense. Therefore, the physiology portion of the course tends to take up more of the lecture time.
You should realize, however, that one cannot understand how something works if one doesn't understand what that something is. So, anatomy and physiology are intimately linked. That means that occasionally, anatomy will be taught in lecture and physiology will be taught in lab. It is just impossible to fully separate them.
Example of the difference between anatomy and physiology:
All living things must be continually using energy. This energy is actually used at the chemical level in our bodies. We can use it to perform chemical reactions, waste some of it as heat (transform energy), or transfer it to other molecules that may need it. If we were to ever stop using energy, we would no longer be living. All of the chemical reactions that are occurring in our bodies at any given time is called our metabolism. You will need to understand certain metabolic processes throughout this year of A&P in order to understand how our bodies work.
Your book describes 5 important factors that our bodies are constantly using/requiring to function normally: water, food, oxygen, heat, and pressure. Water is the main component of our bodies, but it is constantly being used, evaporating, and being excreted... so we need to continue to take it in. Food and oxygen are both used to provide energy for our bodies, and food also supplies other needed chemicals. As you learned in chemistry, temperature is related to kinetic energy, so warmer molecules can undergo reactions more readily than cooler molecules; it is for this reason that heat is important. You'll learn more about how pressure is important when we discuss our cardiovascular system and our respiratory system... but it will come up many more times throughout the year.
Although all those things above are necessary, you know that too much of anything, even a good thing, can be a bad thing. Our bodies have to regulate themselves to remain normal, or in homeostasis. We have to eat when we're hungry, but feel full after eating a while so that we won't over-indulge. Our bodies regulate themselves at all levels (see below for levels of organization); the example above about eating is an example of homeostasis at the level of the entire organism. There is an assignment question about this.
You will be hearing more and more about homeostasis as the year progresses. The main thing to keep in mind is that your body always needs to maintain homeostasis... that means that it is always working toward a goal of homeostasis. Maintaining homeostasis doesn't mean that things just stand still-- it means that your body's chemicals and cells and tissues and organs are all constantly working to be in a normal state, no matter what is going on in your world.
Finally, you should realize that in order for our body to correct itself all the time to maintain homeostasis, it must have a way of checking itself. This is called negative feedback, because when it realizes that one particular process has gone to far, it sends a negative signal back to the overall process to stop it.
We can describe our bodies as having certain levels of organization, as depicted in the picture here. Each of these levels (and those I left out for the sake of room: organelles and atoms) is described in your book.
We will be discussing all of these levels throughout the course. For example, in learning about cancer, one may need to know about organ systems, like the lymphatic system, to understand how cancer may spread throughout the body. But we also have to know about cells, since it is cells that can become cancerous and then divide too much. In addition, we have to know about macromolecules, since it is those macromolecules within the cancerous cells' cytoskeleton that enables the cancerous cells to move about; it is also possible that there are certain genetic predispositions to cancer, so one needs to know about the DNA, another macromolecule, within a cell. I hope this example shows how these levels of life are all important to understanding about the human body.
Read through your book (starting on page 14) to get information about the different organ systems. Basically, we have a system to carry out each general function in our body. So, for example, food processing and break down occur in the digestive system. Cellular wastes are removed from the body (by filtering out blood) by the excretory system. Behavior, sensation, thought, and memory are provided by the nervous system. Etc. Get a feel for these systems now, and you'll be learning about them the rest of the semester.
The items from Chapter 1 that I have left out for now:
The body cavities are described from pages 10 to 14. I find them difficult to thoroughly understand at this point. We will return to this section during the chapter on skin and then again in A&P 2.
The last section of this chapter, from pages 18 to the end, provides you with anatomical terminology. This will be done in lab rather than in lecture.
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