5/19/13 Blackboard Learning System
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File: 4. Study Guide
The study guide is intended to help explain important and difficult sections of each unit. It is intended to supplement
the corresponding figures and discussion found within the textbook.
Unit one serves to introduce you to the basics of anatomy (structure) and physiology (function). A good basic
understanding of the molecules of life and how they can interact within the human body will be important throughout
this course. When required, I will refer you to sections of the introductory chapters so that you can refresh your
memory before applying these concepts in more detailed study of the physiological systems.
Structural and Functional Organization
Beginning at the microscopic level, the body can be studied at increasingly complex structural levels (chemical, cell,
tissue, organ, organ system, organism).
Chapter 2 will give you a detailed introduction to the properties of the chemical compounds from which our bodies are
constructed. The construction of organelles and cells requires the contribution of the special properties of each of the
Tissues are groups of cells that have a similar function (structure). It takes more than one cell to provide enough of a
particular function for something the size of an organism to function properly. By associating together into tissues, this
grouping of cells help one another to perform a specialized function.
Organs are constructed from many tissue types that come together to facilitate the performance of a large function.
The eye, for example, requires a lens, photoreceptors, muscles, and many other tissue types to perform the function of
Organ systems are groups of organs that come together to perform even larger functions. In the cardiovascular
system, the heart, blood, and blood vessels are separate organs that combine their functions for the cardiovascular
system to provide its various roles to the human body or organism.
Homeostasis is an extremely important concept in physiology. It is introduced here, but will come up again as we study
the various organ systems throughout the course.
Many of the responses we can observe in our body are attempts to maintain a state of equilibrium or balance. When we
exercise our muscles produce more carbon dioxide, thereby increasing the level of carbon dioxide in the blood. Our
respiratory system is stimulated to increase breathing rate and depth in order to remove this carbon dioxide and return
the blood levels to normal. This is an example of homeostasis in action.
Ionic Bonding and Dissociation
An atom may gain or lose an electron (negative charge). When this occurs it becomes a positive ion (loss of electron)
or negative ion (gains an electron).
One of the two types of chemical bonding between atoms is ionic bonding. This is a loose association of oppositely
charged ions. These associate because opposite charges attract one another.
Table 2.2 lists important ions found in the body and their chemical symbols. These ions and their importance in
physiological function will come up in every organ system we study throughout the course. It is important to become
familiar with the concept of an ion, the idea of charge (+ or -), and a general idea of the functions of these important
Figure 2.7 illustrates the dissociation of an ionic compound when it dissolves in water. As our bodies are mostly water,
ions are dissociated when in solution in our bodies. Ions that have dissociated in water are often called electrolytes.
This is because they have the capacity to conduct an electrical signal. When we discuss excitable tissues such as
nerve and muscle, we will look at the importance of electrolytes in nerve signal transmission and muscle contraction.