Human body [human anatomy]

The human body is a huge system of relationships and connections, which expresses the entire physical structure of a human being, composed of different types of cells that together form tissues, in turn are organized into systems of organs or systems, or therefore a system in which all the various subsystems or apparatuses interact with each other to produce life, and for this reason it is often seen as a complex system from the physical point of view.

Human anatomy

Human anatomy is the scientific study of the morphology of the adult human body. It is subdivided into gross anatomy and microscopic anatomy (the study of minute anatomical structures assisted with microscopes, and includes histology and cytology). Human anatomy includes several branches:

  • Systematic anatomy, also known as descriptive anatomy, studies analytically the conformation, the relationships, the structure and the development of the different organs of the body, in a healthy state, system by system; it is called macroscopic if it limits its observations to the structures visible to the naked eye, microscopic if it has as its object the intimate structure of the various organs, which it observes with the help of the microscope and with the use of staining methods proper to histology.
  • Topographical anatomy studies the organs synthetically, depending on the location they occupy and their reciprocal relationships; it divides the surface of the human body into territories and regions and in each of these it studies the various layers, from the most superficial to the deepest.
  • Surgical anatomy studies the anatomical problems related to surgical diseases, their symptoms and corresponding interventions; his method of investigation consists of the practical study on the corpse, the observations performed during operations on the patient and the data obtained from the execution of interventions on experimental animals.
  • Pathological anatomy studies the macroscopic and microscopic changes induced in the individual organs by the diseases and aims to trace the changes found to the interpretation of the various clinical manifestations of the disease, to provide confirmation of the diagnosis made in life and to ascertain the cause of death; fundamental investigation method of the academic year pathological is the autopsy, possibly supplemented by histological examination.
  • Radiographic anatomy deals with the nomenclature and appearance of the individual normal parts of the human body as they appear on radioscopy and radiography, i.e. with the particular characteristics that derive from the superimposition of the parts, from the projection and from the different density of the various tissues and organs, typical of the radiological image.

Human anatomy history

The history of human anatomy dates back to a very remote period: papyri, sacred writings, poems and other documents of ancient civilizations testify to a sometimes conspicuous set of anatomical knowledge, which served as the basis for a rudimentary physiology. The practice of embalming, the sacrifices, the dressing of deep wounds were the first occasions for anatomical observations.

The affirmation of anatomy as a science occurred among the Greeks; Alcmeon of Crotone is indicated as the first author of an anatomical work, of which only a few, very short fragments remain; in the Hellenistic era, anatomy reached its peak of splendor in the medical school of Alexandria, mainly thanks to Erofilo and Erasistratus.

In the following centuries, mainly religious obstacles led to a profound involution of anatomical studies: dissections on corpses, judged impious and as such forbidden, were replaced by those on animals, the results of which were applied by Galen without any correction to man; the doctrinal elaboration was limited to an exegesis of the various texts. In this way the anatomical doctrine was burdened and full of errors.

Only around 1315, thanks to L. Mondino de’ Liuzzi, did anatomy find the basis of his investigations and teaching in the dissections on the corpse, without however disengaging from the prevailing dogmatism and therefore without leading to the overcoming of the numerous errors of Galen. In the Renaissance, anatomical studies flourished vigorously, finally taking the path of Galen’s revision. Leonardo da Vinci undertook systematic research, making numerous observations and elaborating the first scientific anatomical iconography, which however was not published and remained unknown to his contemporaries.

The anatomical investigation objectively and systematically conducted found its innovator in A. Vesalius, author of the work De humani corporis fabrica libri septem (1543). The work of Vesalius was continued by G. Falloppia, author, among other things, of research on the ear, bones and genitals. In the context of this renewed interest in anatomical studies, the observations of G. Fabrici d’Acquapendente on the valves of the veins, of B. Eustachio on the ear, of G.C. Casseri on the hearing organ and on the phonation apparatus, by G. Aselli on the chiliferous vessels, by A. Spigelio on the legate, by J.G. Wirsung, T. Wharton and N. Stenone on the glands, by T. Willis on the nervous system. In the 17th century. the most impressive contributions to anatomical research were brought by M. Malpighi and A. van Leeuwenhoek, who first resorted to the aid of the microscope.

Malpighi, by describing the blood corpuscles and identifying fine structures in the skin, spleen, kidney, lung, opened the vast chapter of microscopic anatomy and tissue anatomy (histology). In the same period, F. Ruysch perfected the technique of injecting vessels with colored materials, and with this shrewdness he was able to describe the valves of the lymphatic vessels and the disposition of the vessels within various organs. Of particular importance were the researches of A.M. Valsalva on the ear and G.B. Santorini on the musculature of the face and larynx. During the 18th century. fundamental was the descriptive contribution brought by G.B. Morgagni, to whom we owe the description of numerous anatomical formations as well as the merit of having laid the doctrinal and methodological foundations of pathological anatomy. Other notable contributions also came from W. Hunter on the anatomy of the pregnant uterus, J. Hunter on the structure of the teeth and D. Cotugno on the cerebrospinal fluid.

Thanks to the possession of an increasingly perfected investigation technique and the vastness of the topics investigated, in the following centuries, in addition to a greater rigor of descriptions, the formation of specialized branches was outlined within the common doctrine. Thus, while descriptive anatomy received the contribution of L. Rolando’s studies on the brain, by F.G. Henle on the kidney, by F. Pacini on sensory endings, by A. Corti on the hearing organ, the studies of topographical anatomy and surgical anatomy gradually developed in Italy, initiated by M.V. Malacarne and A. Scarpa, and pathological anatomy, comparative anatomy, anthropometry and biometry acquired importance of independent branches of science. At the end of the 19th century, microscopic anatomy developed, thanks to the introduction of more and more suitable means of staining and the use of more perfected microscopes and microtomes.

In topographical anatomy, the mechanical sections of frozen or formalin-fixed cadavers allowed a clearer view of the contiguity relationships between the various organs. During the 20th century. radiological techniques made it possible to conduct morphology research in vivo. Microscopic anatomy, for its part, has deepened its investigation possibilities with the aid of electron microscopy. The improvement of the means of investigation has extended the research of experimental morphology – a chapter of anatomy aimed at studying the causes that determine the forms – also to organs and organisms, while in the past these were almost exclusively limited to embryos.