Human Anatomy - Kotsan I. Y. 2009

The place of man in nature
Structural elements of the human body
The concept of organs, systems, and apparatuses

An organ (organum — an instrument or tool) is a part of the body that has a specific shape and Structure, occupies a definite position within the Organism, and performs a specialized function.

Various tissues take part in The formation of any organ, but one of them is primary, functional, and determines the Specific features of its Structure and function. For bones, this is Bone tissue; for Muscles, muscular tissue; for the Brain, Nervous Tissue; and for glands, Epithelial Tissue. Other tissues within the organ perform supportive Functions. For instance, Connective Tissue forms the organ's connective-tissue framework, known as the stroma; epithelial tissue lines the mucous membranes of the respiratory and digestive systems; and muscular tissue contributes to the Formation of the walls of hollow Organs. Examples of organs include bones, muscles, glands, Lungs, Stomach, Liver, etc.

To perform a wide range of functions, a single organ is often insufficient. Therefore, complexes of organs—systems—arise.

An organ system is a group of organs that have a similar overall structure, share a common origin, and perform the same function within the organism. For example, the Skeletal System is a collection of bones with a uniform structure, similar function, and common origin. The same can be said for the muscular or nervous systems. The Human Body comprises the following systems: skeletal, muscular, digestive, respiratory, urinary, reproductive, circulatory, lymphatic, immune, nervous, endocrine, and Sensory systems.

An apparatus is a collection of organs or systems that differ in structure and origin, yet perform a joint function. For instance, The Musculoskeletal System includes both the skeletal and muscular systems; the urogenital (or urinogenital) apparatus combines two Organ Systems that are anatomically and physiologically distinct, yet closely linked topographically, by origin, and partially in function—namely, the Urinary System and the Reproductive System.

The combination of organ systems and apparatuses forms an integrated human organism, in which all constituent parts are interconnected. The primary role in integrating the organism into a unified whole belongs to the nervous, cardiovascular, and endocrine systems. These three systems provide the Neurohumoral regulation of bodily functions.

The human body is closely linked with its environment and can only survive under specific environmental conditions to which it has adapted and without which it cannot exist. A continuous METABOLISM with the surrounding external nature is an essential condition of life. When metabolism ceases, life ceases as well.

The human body comprises the soma (from the Greek soma — body), which conventionally includes the Skin, bones, joints, muscles, and Sense Organs, as well as Internal Organs located within Body Cavities (thoracic, abdominal, and pelvic). The internal organs include those of the digestive, respiratory, and urogenital systems. Blood Vessels and nerves supply and branch throughout both the soma and the internal organs.

The fundamental principles of body architecture are polarity (different structure and function of the poles), segmentation (most clearly preserved only in the trunk), bilateral Symmetry (similarity of sides, though not absolute), and correlation (the interrelationship between individual parts).

In the course of its evolution and development, the human body has adapted to its surrounding environment. As a result, a specific equilibrium has been established between the organism and the concrete conditions of the external world. This equilibrium, achieved through specific morphological and functional Features of the organism, is referred to as the norm, and the corresponding body structure as normal. Since various factors of the external and internal environment affect the organism, its structure—as well as that of its individual organs and systems—varies; however, under normal conditions, this Variability does not disrupt the established equilibrium with the environment. Thus, the norm is not something fixed and immutable, as metaphysics teaches; it is diverse and represented by numerous structural variations that collectively constitute the individual Variability of the organism, determined by both heredity and environmental factors.

The structure of the organism and its individual organs exhibits many variations—Variants of the norm (variatio — modification). According to variational statistics, they form a variation curve (or series), at the edges of which lie the extreme forms of individual variability. Consequently, the norm is a harmonious combination of structural variants and correlations of bodily traits that are characteristic of humans as a species and ensure the full execution of biological and social functions.

Every human being is unique and differs from others by individual, exclusively personal characteristics; at the same time, humans belong to a single species and share the same structural blueprint.

An anomaly (from the Greek anomalos — unlike, irregular) is a deviation from the norm, expressed to varying degrees. These also have subtypes: some result from improper development yet do not disrupt the equilibrium established between the organism and the environment, thereby having no impact on function. Examples include dextrocardia (right-sided Heart placement) or situs inversus (transposition of internal organs). Other anomalies are accompanied by disorders of bodily functions or individual organs, disrupting the organism's equilibrium with the environment (e.g., cleft palate) or even rendering it completely unviable (e.g., Acrania—absence of the Skull, acardia—absence of The Heart, etc.). Such severe developmental defects are termed malformations (or monstrosities). The branch of anatomy and Embryology that studies anomalies and malformations is called teratology (from the Greek teratos — wonder, monster) and falls under pathological anatomy.