Understanding Anatomy & Physiology: A Visual, Auditory, Interactive Approach Third Edition

Book Preface

Even as you read this sentence, your body is performing amazing feats. Electrical impulses are rocketing through your brain at more than 200 miles per hour. Hundreds of muscles continually tense and relax to keep you in an up-right position and to allow your eyes to track across the words on this page. A specific muscle—your heart—is con-tracting and relaxing at regular intervals to propel blood throughout your body. In fact, your blood will make two complete trips around your body before you finish reading this preface.
Even more amazing is the fact that the vast array of cells, tissues, organs, and organ systems making up your body arose from just two simple cells—an egg and a sperm. Consider, too, that you are genetically unique: out of the more than 6 billion people populating the earth, no two individuals are completely alike. That is reason to marvel.
Artists and scientists have long been captivated by the human body. For centuries, artists have studied the body’s outward form, focusing on the movement and shape of muscles and bones when rendering works of art. Scientists, on the other hand, yearned to discover the mysteries inside the body. For almost 3,000 years, scientists have explored the depths of the human body: not just how it is put together, but how and why it functions as it does.
Exploration continues today, with the latest discovery being that of the human microbiome, a vast system of microorganisms living on and in the human body. We now know that human health is not a matter of human DNA alone. Rather, how your body functions, your propensity for certain diseases, how you respond to medications, and even how you think and behave, is a matter of microbial cells and human cells working together.
If that’s not enough, scientists also recently discovered—contrary to what today’s practicing physicians were taught in medical school—that the body’s lymphatic system, and therefore immune system, extends to the brain. This is significant. Knowing that the lymphatic system infiltrates the brain has triggered such research questions as, “Could sluggish lymphatic flow contribute to the development of Alzheimer’s or Parkinson’s diseases?”
The human body is an intriguing landscape, and
your journey to discovery begins with reading this book. Contained on these pages is information about which ancient scientists only dreamed. This information will enlighten you about your own body; what’s more, it
will arm you with knowledge that is foundational to any health- or sports-related career.
Truly, before you can understand a body in illness, you must understand how it functions in health. For example, without a thorough knowledge of fluid and electrolyte balance, how can you explain why chronic vomiting or diarrhea can cause irregular electrical activity in the heart? Without an understanding of how the cardiovascular and respiratory systems interrelate, how will you grasp why chronic lung disease can lead to heart failure? How can you appreciate the need for caution in administering antibiotics without an understanding of the human microbiome? Consequently, you must learn—really learn and not just memorize— the information contained in this book.
There is much to learn, to be sure; but don’t be overwhelmed. Understanding Anatomy & Physiology breaks the information into “bite-sized” pieces, making topics easier to understand and also to remember. As you read the text—and you must read the text—you’ll be drawn naturally to vibrant figures that will illuminate what you’re reading. Being able to see a structure while you’re reading about it will make learning easier. Also, consult the inside back cover of this book to discover your particular learning style; then take advantage of the ancillary materials most likely to help you learn.
You can learn this. By the end of this course, understanding the body’s form and function can become second nature. Although tackling this class may seem like an impossible marathon, you can indeed get to the finish line. As with any marathon, the keys are to follow a plan (read the book); don’t skip workouts (review and study daily); and take it step by step (study each chapter in sequence). You will get there.