Contents | Introduction | Cells | Epithelia | Connective Tissue | Blood | Cartilage | Bone | Muscle | Nerves | Skin | Circulatory System | Respiratory System | Oral Cavity | Alimentary Canal | Pancreas Liver And Gallbladder | Urinary System | Immune System | Male Reproductive System | Female Reproductive System | Endocrine System | The Senses |Appendix | Glossary
Associate Professor Departments of Cellular and Structural Biology and Otolaryngology University of Colorado School of Medicine Denver, Colorado
Departments of Cellular and Structural Biology and Otolaryngology University of Colorado School of Medicine Denver, Colorado
THIS BOOK is dedicated to the cells and tissues it describes; to the Master Builder who oversaw, and oversees, their creation and evolution; and to Professor Keith Roberts Porter, who taught us how to look at, study, photograph, and, best of all, appreciate the elegant cells and tissues of which we ourselves are made.
FORTUNATELY, for students and professors alike, the learning of histology, or microanatomy, can be simple and enjoyable. This atlas grew out of a general principle of learning: that anything is simple once you understand it. We have found that histology is very simple to understand once you learn how to see the material. Histology is a visual art that, somewhat ironically, is based on the study of structures that cannot be seen. In order to study microanatomy, then, we need optical aids. The major optical instrument available to the student is the light microscope. Wondrous though the light microscope is, however, it has one serious shortcoming: it does not show cell boundaries, because each cell is surrounded by a structure called the cell membrane that lies beyond the resolving power of the light microscope.
This severe limitation of the light microscope can cause considerable confusion in the laboratory portion of a microanatomy course, because students using the microscope for the first time are unable to tell where one cell ends and another begins. How can the student be expected to study the microscopic anatomy of cells and tissues if he or she cannot see the size and shape of the fundamental unit of structure - the cell?
This atlas came into being to solve that problem. Fortunately, another kind of microscope, the transmission electron microscope, can clearly resolve cell membranes, even at low magnification - well within the magnification range of the light microscope. Unfortunately, electron microscopes are too expensive to buy and maintain for general student use. Although many superb photographs taken with the electron microscope are available, most of these are taken at high magnification, beyond the range of the students' light microscopes, and novices find it difficult to make the perceptual leap from what they see at low magnification by light microscopy to the high-magnification images of tissues available in the literature.
To address this problem, we have assembled a collection of light and electron micrographs of the same tissues in which the electron micrographs are taken at low magnification. In many cases, we show matched pairs of light and electron micrographs of serial "thick" and "thin" sections of the same tissue block, photographed at the same magnification and described with identical labels. We have found the use of matched light and electron micrographs of the same tissue to be an extremely effective teaching tool that allows students to learn the material rapidly. With practice, students develop a kind of "x-ray vision," formerly the province of experienced research electron microscopists, with which they can mentally superimpose images observed by low-magnification electron microscopy onto the fuzzy images seen with the light microscope. This allows students to accurately identify structures that formerly were "invisible" to them by light microscopy.
We firmly believe in the saying, "A picture is worth a thousand words." Consequently, we have supplied each plate of pictures with a text description of about a thousand words. The atlas is organized to maximize ease of use and speed of learning. First, it is subdivided into 20 major chapters that correspond to 20 major areas of study - starting with cells, moving into tissues, and progressing into organs. Where necessary, each chapter starts off with an overview that gives perspective to the specific images that are to follow. Next, a series of plates is presented. Each plate has a one-page description that allows the reader to look back and forth between text and micrograph with no irksome page-turning. The important structures on each plate are labeled, and the labels are identified in the figure legend and used in the text.
We fully realize that, although histology is a visual art, we need to use descriptive anatomic terms when talking about the material. Since the study of microanatomy may be the student's first foray into the formidable world of anatomic terminology - whether the student is an undergraduate, a medical student, a dental student, a graduate student, a nursing student, or simply a curious person who wants to understand his or her own inner workings - the terminology can be bewildering. To that end, we have italicized every key word as it is encountered for the first time in the atlas and have written a complete glossary, placed at the end of the book, that gives a succinct working definition of each term.
Throughout this atlas, we have used human and primate material wherever possible. In certain cases, where a very small organ was required (each of our tissue samples had to be small enough to fit into a 1-mm-wide slot in an electron microscope specimen grid) we chose to use a small mammal, since primate organs tend to be rather large. In other cases, when our fixation of primate material did not meet our high standard of tissue preservation, we chose available mammalian material rather than take a monkey's life for a particular photograph. Wherever possible we used animals whose lives were to be terminated during the course of biomedical research.
This atlas is not a comprehensive treatment of the subject matter. To make it so would have made the book very expensive. We are aware of the increasing strain on the student's pocketbook and intend this atlas to be affordable, which means its length must be limited. We have, nevertheless, attempted to offer a strategic sampling of key tissues and organs that should give the student a strong foundation in visual histology and have presented a large number of photomicrographs. In a sense, this atlas is as much of an art book as it is a science book, for good science, done properly, is an art form. Also, the cells and tissues of which we are made are intrinsically of great aesthetic beauty; for in their creation, form has followed function.
DAVID T. MORAN
J. CARTER ROWLEY, III
THERE are a number of people we wish to thank who have helped create this atlas. Dr. Keith Porter offered much-needed encouragement at the onset of the project and generously supplied Figure A in Plate 10-4. Cecile Duray-Bito did a superb job with the drawings that appear in the overviews, and was a great pleasure to work with. Pam Eller and Kathy Ferguson were both extremely helpful in many phases of materials preparation. Drs. Nolan Rucker and James Stevens generously offered their veterinary skills in obtaining primate tissues. Dr. Bruce Jafek kindly supplied us with tissues from the nose and ear for our chapter on the senses; Drs. Cedric Raine, Stephen Roper, and Thomas Mehalick were extremely helpful in providing tissues for the chapter on nerves when our own fixations fell short of the mark. Dr. Stanley Gould also helped by supplying fresh surgical specimens for the chapter on the female reproductive system.
Shelley Rowley offered much-needed encouragement and support throughout the entire project. Dr. Kimberly Janes was a great help; being a student of medicine at the time this was written, she offered most valuable and incisive critiques of the manuscript, and was able to present us with the "student's-eye view" that helped us to maintain our focus. Jack Rowley generously provided, in addition to encouragement, the tranquil setting in which much of the thinking and writing for this book were done. In addition, we thank Ron Metusalem and the Tilloo Cay Foundation for Biological Research for their generous support throughout this project. Finally, we are most grateful to our publishers, Lea & Febiger, for their faith in us, their encouragement, their cooperation, and their patience - which, it seems, has no bounds.