ANATOMY

 

Anatomy (Grk., anatome, “dissection”), branch of natural science dealing with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. For centuries anatomical knowledge consisted largely of observations of dissected plants and animals. The proper understanding of structure, however, implies knowledge of function in the living organism. Anatomy is therefore almost inseparable from physiology, which is sometimes called functional anatomy. As one of the basic life sciences, anatomy is closely related to medicine and to other branches of biology.

 

It is convenient to subdivide the study of anatomy in several different ways. One classification is based on the type of organisms studied. Anatomy can also be subdivided into biological processes, for example, developmental anatomy, the study of embryos, and pathological anatomy, the study of diseased organs. Other subdivisions, such as surgical anatomy and anatomical art, are based on the relationship of anatomy to other branches of activity under the general heading of applied anatomy. Still another way to subdivide anatomy is by the techniques employed, for example, microanatomy, which concerns itself with observations made with the help of the microscope.

 

History of Anatomy

The oldest known systematic study of anatomy is contained in an Egyptian papyrus dating from about 1600 BC. The treatise reveals knowledge of the larger viscera but little concept of their functions. About the same degree of knowledge is reflected in the writings of the Greek physician Hippocrates in the 5^th century BC. In the 4^th century BC Aristotle greatly increased anatomical knowledge of animals. The first real progress in the science of human anatomy was made in the following century by the Greek physicians Herophilus and Erasistratus, who dissected human cadavers and were the first to distinguish many functions, including those of the nervous and muscular systems. Little further progress was made by the ancient Romans or by the Arabs. The Renaissance first influenced the science of anatomy in the latter half of the 16^th century.

 

               

 

Modern anatomy began with the publication in 1543 of the work of the Belgian anatomist Andreas Vesalius. Before the publication of this classical work anatomists had been so bound by tradition that the writings of authorities of more than 1000 years earlier, such as the Greek physician Galen, who had been restricted to the dissection of animals, were accepted in lieu of actual observation. Vesalius and other Renaissance anatomists, however, based their descriptions on their own observations of human corpses, thus setting the pattern for subsequent study in anatomy.

 

Republic of Togo ,  Proof

Painting of Rembrandt “ Anatomy Lesson of Dr.Deyman ”

This painting was partly burnt unfortunately.

There is only able to see the hands of Dr.Deyman.

 

The 17^th century invention of the compound microscope led to the development of microscopic anatomy, which is divided into histology—the study of tissues—and cytology—the study of cells. Under the leadership of the Italian anatomist Marcello Malpighi, the study of the microscopic structure of animals and plants flourished during the 17^th century. Many great anatomists of the period were reluctant to accept microscopic anatomy as part of their science. By contrast, modern anatomy is studied usually with the aim of correlating the structure of organisms as seen by the naked eye with their structure as revealed by more refined methods of observation.

 

Pathological anatomy was established as a branch of the science by the Italian physician Giovanni Morgagni, and in the late 18^th century comparative anatomy was systematized by the French naturalist Georges Cuvier.

              

      From Yemen Human anatomy              Sweden, Human anatomy stamps from left to right middle ear,

                                                                                              Neuron, nerve synapse, brain and eye

 

In the late 18^th and early 19^th centuries restrictive legislation limiting the use of unclaimed human bodies for the study of anatomy and surgery gave rise to an era of body snatching in England and the United States. The scandals arising from this practice forced the repeal of the English restrictions in 1832 and the enactment of more advanced legislation.

 

    

Microscopic anatomy developed rapidly in the 19^th century. During the second half of the century many basic facts about the fine structure of organisms were discovered, largely as a result of greatly improved optical microscopes and of new methods that made cells and tissues easy to study with this instrument. The method of microtome, the cutting of tissue into thin, practically transparent slices, was perfected. Microtome was rendered incomparably more valuable by the application to the tissue slices of various types of dyes and stains that make it much easier to see various parts of the cell.

 

Knowledge of microscopic anatomy was greatly expanded during the 20^th century as a result of the development of microscopes that provided much greater resolution and magnification than had conventional instruments, thus revealing formerly unclear or invisible detail; and expanded laboratory techniques helped facilitate observation. The ultraviolet microscope allows the observer to see more because the wavelengths of its probing rays are shorter than those of visible light (the resolving power of a microscope is inversely proportional to the wavelength of the light used). It also is used to emphasize particular details through selective absorption of certain ultraviolet wavelengths. The electron microscope gives even greater magnification and resolution. These tools have opened up formerly unexplored fields of anatomical investigation. Other modern microscopes have made visible unstained and living materials that would be invisible under the conventional microscope. Two examples are the phase-contrast microscope and the interference microscope. Through utilization of ordinary light beams, both these instruments differentiate parts of living, unstained cells.

 

      

Johannes Evangelista Purkinje 1787 – 1869

 

Czech physiologist, who was a pioneer in the fields of histology, embryology, pharmacology, and the workings of the eye, heart, and brain. Born in Libochovice and educated at the University of Prague, he became Professor of Physiology at the University of Breslau,(now Wroclaw, Poland) and later at the University of Prague. He invented the microtome, an instrument for slicing thin portions of tissue for microscopic examination. His histological discoveries include the sweat glands; the neurons, called Purkinje's cells, of the cerebellum; the muscular fibres, called Purkinje's fibres, in the tissue of the ventricles of the heart; and the nucleus of the human egg, called Purkinje's germinal vesicle. He also investigated the structure, function, and diseases of the eye; the effects of such drugs as opium; and identification by fingerprinting.

 

Theodor Schwann 1810 – 1882

German physiologist, generally considered the founder of modern histology, the study of the structure of plant and animal tissues.

 

Schwann was born in Neuss and educated at the Universities of Bonn, Würzburg, and Berlin. He was Professor of Anatomy at the University of Louvain in Belgium; thereafter until his death he was associated with the University of Liège, also in Belgium, serving as Professor of Anatomy from 1848 to 1858, when he became Professor of Physiology. Schwann ascertained the physiochemical nature of life by applying the cell theory of the German botanist Matthias Jakob Schleiden to the evolution of animal life. He also demonstrated that the mature tissues of all animals are traceable to embryonic cells. While assisting the German physiologist Johannes Müller in the Anatomical Museum of Berlin, Schwann discovered pepsin, the digestive enzyme, in the stomach epithelium, or membrane tissues, of animals. He also conducted valuable research on the processes of fermentation, putrefaction, and muscular and arterial contraction. His principal work is Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals.

 

Leonardo da Vinci 1452 – 1519

Florentine artist, one of the great masters of the High Renaissance, celebrated as a painter, sculptor, architect, engineer, and scientist. His profound love of knowledge and research was the keynote of both his artistic and scientific endeavors. His innovations in the field of painting influenced the course of Italian art for more than a century after his death, and his scientific studies—particularly in the fields of anatomy, optics, and hydraulics—anticipated many of the developments of modern science.

 

Scientific and Theoretical Projects

As a scientist Leonardo towered above all his contemporaries. His scientific theories, like his artistic innovations, were based on careful observation and precise documentation. He understood, better than anyone of his century or the next, the importance of precise scientific observation. Unfortunately, just as he frequently failed to bring to conclusion artistic projects, he never completed his planned treatises on a variety of scientific subjects. His theories are contained in numerous notebooks, most of which were written in mirror script. Because they were not easily decipherable, Leonardo's findings were not disseminated in his own lifetime; had they been published, they would have revolutionized the science of the 16th century. Leonardo actually anticipated many discoveries of modern times. In anatomy he studied the circulation of the blood and the action of the eye. He made discoveries in meteorology and geology, understood the effect of the moon on the tides, foreshadowed modern conceptions of continent formation, and surmised the origin of fossilized shells. He was among the originators of the science of hydraulics and probably devised the hydrometer; his scheme for the canalization of rivers still has practical value. He invented a large number of ingenious machines, many potentially useful, among them an underwater diving suit. His flying devices, although not practicable, embodied sound principles of aerodynamics.

 

The discovery of X-rays by the German physicist Wilhelm Roentgen enabled anatomists to study tissues and organ systems in living animals. The first X-ray photograph, taken in 1896, was of a human hand. Today's techniques permit three-dimensional X-ray photographs of the soft tissues of the viscera after ingestion of special opaque fluids, and of “slices” of the body with computer-aided X-ray beams. The latter is called computerized tomography, or CT scanning. Other noninvasive techniques that have been developed include the use of ultrasonic waves for imaging soft tissues and the application of nuclear magnetic resonance systems to research and diagnosis.

      

 

Another 20^th century technique of anatomical investigation is tissue culture, which involves the cultivation of cells and tissues of complex organisms outside the body. The technique permits the isolation of living units so that the investigator can directly observe the processes of growth, multiplication, and differentiation of cells. Tissue culture has thus added a new dimension to anatomical science.