The simplest way to study human anatomy is the observation of surface structure, for example in performing a physical examination or making a clinical diagnosis from surface appearance. But a deeper understanding of the body depends on dissection—the careful cutting and separation of tissues to reveal their relationships. Both
anatomy1 and dissection2 literally mean "cutting apart"; dissecting used to be called "anatomizing." The dissection of a dead human body, or cadaver,3 is an essential part of the training of many health science students (fig. 1.1). Many insights into human structure are obtained from comparative anatomy—the study of more than one species in order to learn generalizations and evolutionary trends. Students of anatomy often begin by dissecting other animals with which we share a common ancestry and many structural similarities.
Dissection, of course, is not the method of choice when studying a living person! Physical examinations involve not only looking at the body for signs of normalcy or disease but also touching and listening to it. Palpation4 is feeling structure with the fingertips, such as palpating a swollen lymph node or taking a pulse. Auscultation5 (AWS-cul-TAY-shun) is listening to the natural sounds made by the body, such as heart and lung sounds. In percussion, the examiner taps on the body and listens to the sound for signs of abnormalities such as pockets of fluid or air.
Structure that can be seen with the naked eye, whether by surface observation or dissection, is called gross anatomy. Ultimately, though, the functions of the body result from its individual cells. To see those, we usually take tissue specimens, thinly slice and stain them, and observe them under the microscope. This approach is
3cadere = to fall or die
4palp = touch, feel
5auscult = listen
Saladin: Anatomy & I 1. Major Themes of I Text I I © The McGraw-Hill
Physiology: The Unity of Anatomy and Physiology Companies, 2003 Form and Function, Third Edition called histology6 (microscopic anatomy). Histopathology is the microscopic examination of tissues for signs of disease. Ultrastructure refers to fine details, down to the molecular level, revealed by the electron microscope.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.