Human Anatomy Part 1 - K. A. Dyubenko, A. K. Kolomiysev, Y. B. Chaykovsky 2002

Special Part
Osteology, osteologia [the study of bones] - General Information
The concept of norm, normal variants, and anomalies

Osteology (from the Greek osteon – bone, logos – doctrine) is a branch of anatomy that studies the Skeletal System of The Human Body, systema skeletale. The fundamental principle of osteology is that the body's skeletal system is structured to achieve maximum strength with minimum weight (P. F. Lesgaft). Osteology is divided into general and special:

- general osteology examines the skeletal system as a whole, including its divisions, Sexual Dimorphism, Classification and Structure of bones as Organs in relation to their function, chemical composition, physical properties, development, and the Influence of External factors on their structure;

- special osteology examines The structure of individual BONES OF THE Skeleton.

Bones, ossa, serve as attachment sites for Muscles and many Internal Organs. They form the structural framework of the human body, which performs a protective function (vertebral canal, cranial cavity, thoracic cage, pelvis). Together with muscles, joints, and tendons, bones form a system of levers that carry out support and locomotor Functions for the human body; thus, they constitute The Musculoskeletal System, which is divided into two parts: the passive component – Bones and Their Joints – and the active component – striated muscles.

As part of the musculoskeletal system, bones withstand body weight and heavy loads associated with locomotion in space and the movement of individual body parts. Alongside mechanical functions, bones also perform certain metabolic functions: they participate in METABOLISM, particularly Mineral Metabolism, due to their ability to rapidly release or store Calcium and phosphorus in the Blood, thereby maintaining body Homeostasis (regulated by thyrocalcitonin and parathormone).

Bones contain Cytology/practical/86.html">Red Bone Marrow, the primary hematopoietic organ and an organ of immune defense. The structural basis of bones is Bone tissue, which stimulates bone marrow hematopoiesis.

The adult human body contains over 200 bones of various SHAPES AND SIZES, externally covered by the periosteum, and at articular surfaces – by articular Cartilage. Blood Vessels supply Nutrition to the bones. Connected to each other by connective, cartilaginous, and Bone Tissues, the bones of the human body form the skeleton, skeleton (Fig. 16).

The skeleton, systema skeletale, is a system of hard, predominantly bony and cartilaginous structures that form the foundation of the human body. It performs the functions of support and protection of internal organs from mechanical damage, along with A number of biological functions. In addition to the osseous skeleton, there is also a "soft skeleton" formed by tendons, ligaments, loose Connective Tissue, joint capsules, fibrous sheaths, and internal organ membranes (I. P. Matyushenkov). The mass of the skeleton is 5–6 kg.

Class="center">

Fig. 16. Skeleton, skeleton (anterior view)

The human skeleton is divided into the Axial Skeleton, skeleton axiale, and the Appendicular Skeleton, skeleton appendiculare. The axial skeleton consists of THE Vertebral Column, Skull, and thoracic cage; the appendicular skeleton consists of the Pectoral Girdle and the free upper limb, and the Pelvic Girdle and the free lower limb.

The human skeleton is formed by over 200 bones: 36–40 are unpaired; 23 bones form the skull; 33–34 vertebrae form the vertebral column; 24 Ribs and the Sternum form The thoracic cage; 64 bones comprise the upper limbs, and 62 comprise the lower limbs. The number of skeletal bones may vary depending on the presence of accessory and sesamoid bones, predominantly in the skull, hands, and feet. (Sesamoid bones, ossa sesamoidea, are small bones that serve as permanent or inconstant Accessory structures of joints. They act as unique pulleys for joints, increasing the angle of attachment of a Muscle tendon to the bone.)

The dimensions and Proportions of the skeleton depend on sex, typological, and individual characteristics. The female skeleton differs from the male skeleton by having thinner and lighter bones, a greater lumbar curvature, a short and wide sacrum, a low and wide pelvis, a relatively greater width and rounded shape of the skull, and a narrower and longer thoracic cage. Together with muscles, subcutaneous adipose tissue, and other anatomical structures, the skeleton influences the surface relief and posture of the human body.