Human Anatomy - Kotsan I. Y. 2009

Introduction
Methods of Anatomical Research

When studying human anatomy, various Methods developed over the long history of anatomical science are employed. Modern methods for examining human morphological features are quite numerous and sophisticated. They can be divided into two groups. The first group of methods is used to study The Structure of the body using cadaveric material, while the second group is applied to the living human body.

The first group comprises principally the methods of classical anatomy and other sciences that have been adapted for anatomical purposes and refined in accordance with the current level of science and technology.

The dissection method. It allows The Study of the structure and mutual arrangement (topography) of Organs using simple anatomical instruments (scalpel, forceps, etc.). This is the oldest method, which remains leading to this day.

The macro-microscopic method. Developed in the early 20th century by Academician V.P. Vorobyov, this method involves fine dissection of objects under a falling drop of Water and the study of their structural features using a binocular magnifier. It is used to investigate objects that lie on the border between macro- and microscopic visibility.

The fixation or preservation method (embalming of cadavers). It ensures the long-term preservation of anatomical specimens and even entire cadavers, preventing putrefaction and decay. Work on cadavers utilizes methods of layer-by-layer tissue dissection followed by the preparation of their structural components to be studied. To facilitate this work and protect the specimen from decay, it is fixed with special solutions, most commonly a weak formalin solution.

The injection or filling method. This involves filling hollow organs with colored masses, followed by clearing the organ's parenchyma and dissecting the anatomical structures.

The corrosion method. Used in studying the vascular bed and Internal Organs, this method is similar to injection: the cavities of organs or vessels are filled with hardening masses (plastics, liquid metal), after which the organ is immersed in strong acid or alkali, which destroys all Tissues, leaving a cast of the injected formations.

The method of cutting frozen cadavers. Frozen cadavers are sectioned in three perpendicular directions. Because the frozen organs do not shift, their mutual arrangement can be precisely traced at various body levels under normal conditions, as well as during various physiological states and pathological processes. This method was developed by the renowned anatomist and surgeon N.I. Pirogov.

The maceration method. This involves soaking cadavers by immersing them in water or special fluids for an extended period. This method allows for the Isolation of the Skeleton, as well as individual bones, to study their structure.

To solve A number of anatomical tasks, histological and histochemical methods are used, wherein the object of study is examined at magnifications provided by a Light Microscope.

Electron Cell/15.html">Microscopy is also widely used in anatomy, allowing the visualization of ultramicroscopic structures at the cellular and organellar levels. Promising methods include scanning and transmission electron microscopy, which provide a three-dimensional image of the object under study at both low and high magnifications. Biomechanical and mathematical methods are also frequently employed.

All of the aforementioned methods are used when working with cadaveric material. However, as P.F. Lesgaft wrote, when studying anatomy, the living Organism should always be the primary object, and all research begins with its observation; the dead specimen should serve solely to verify and Supplement the Study of the living organism.

The second group of methods used in human anatomy comprises those applied to study the STRUCTURE OF THE living organism.

The somatoscopic method—visual inspection of The Human Body and its individual parts. This method allows for the determination of chest shape, the degree of development of individual Muscle groups, subcutaneous adipose tissue, spinal curvatures, etc. In a clinical Setting, somatoscopy is accompanied by Palpation (feeling), Percussion (tapping), and Auscultation (listening) of specific body areas.

The somatometric or anthropometric method—the study of body structure by measuring the dimensions of its individual parts and calculating their ratios, which determine body proportions. This method makes it possible to study body composition—The ratio of muscle, bone, and adipose tissue, joint mobility, body constitution, etc.

The X-ray method and its modifications (fluoroscopy, radiography, roentgenkymography, roentgendensitometry, etc.). This method was first applied in anatomy by domestic scientists P.F. Lesgaft and V.M. Tonkov. It enables the study of the structure and topographic features of organs in a living person both during specific periods of their functional activity and in relation to age-related dynamics. The recent development of color fluoroscopy combined with tomography has significantly expanded the capabilities of the X-ray method: anatomical formations in a living organism can now be studied even in color imaging. The newest methods of X-ray research include: electroradiography, which produces X-ray images of soft tissues (Skin, subcutaneous tissue, ligaments, Cartilage, the Connective Tissue framework of parenchymatous organs, etc.); tomography, which provides X-ray images of structures lying in a predetermined plane; computed tomography, which displays a three-dimensional image synthesized from A large number of individual tomographic slices on a television screen; and roentgendensitometry, which allows for the determination of mineral salt content in bones *in vivo*.

The endoscopy of internal organs. Using fiber-optic technology, it has become possible to examine the internal surfaces of the digestive and respiratory tracts, the Urogenital apparatus, The Heart, and Blood Vessels in a living person, as well as to study the processes occurring within them.

Modern anatomy has also been enriched by such new Research Methods as radioisotope scanning, ultrasonic diagnostic imaging (ultrasound), and nuclear magnetic Resonance (NMR).

The radioisotope method makes it possible to determine biochemical structures, anatomo-topographical characteristics, morphological changes in organs and systems, and their functional state using radioactive compounds. The radioisotope method is based on recording the radiation intensity of a radionuclide administered into the organism or into samples of its biological environments. Radioactive iodine isotopes, Amino Acids (thymidine, uracil), and Hormones are used as radioactive markers.

The ultrasonic diagnostic method enables the Determination of the Anatomical Structure of the object under study, morphological changes in organs and systems, their functional state, and pathological changes through the action of ultrasonic waves. Echographic, transmission, and Doppler-based methods are utilized for this purpose.

The echographic method is based on recording reflected signals (echoes) from boundaries between media with different acoustic impedances to obtain information about the anatomical structure of the studied object. This method is used for diagnosing space-occupying lesions of the Brain (echoencephalography), eye diseases (echoophthalmology), the condition of abdominal organs, cardiovascular diseases (echocardiography), and the like.

The transmission method is based on registering signals that have passed through the object under study. Such signals contain information about the transit time of the ultrasonic wave and, accordingly, the dimensions of the organ being studied. This method is used for metrological purposes, specifically to determine the size of the studied object.

The method based on the Doppler effect—that is, recording Changes in the frequency of signals reflected from moving boundaries between media—provides information about the dynamics of internal organs. It is used primarily for investigating The Cardiovascular system.

Using nuclear magnetic resonance (NMR), one can reveal not only anatomical details of structure but also obtain information about biophysical processes occurring in tissues; it allows for non-invasive investigation of biochemical processes in organs and tissues, as well as the determination of the concentration and Chemical Structure of environments at THE MOLECULAR LEVEL, along with their dynamic state in the case of moving Body Fluids (blood, lymph).