Classification of human bones and their joints

Bone is the hardest substance after the tooth enamel, present in the human body and consisting of a special type of connective tissue. Its characteristic features include the presence of a solid, impregnated with mineral salts, fibrous intercellular substance and star cells, equipped with numerous processes. Classification and structure of bones allow us to understand how important the role of the musculoskeletal system in the body.

Classification of bones

Each bone is an independent organ consisting of two parts. The outer part is the periosteum, and the inner part is formed by a special connective tissue. Their cavities are the site of the most important human hematopoietic organ.

Classification of bones in form provides for the presence of the following groups:

• Long or tubular;
• Short, which is otherwise called spongy;
• Flat or wide;
• Mixed, sometimes called abnormal;
• Airborne.

In the long (tubular) bone, the middle part is elongated, cylindrical or trihedral. This part is called diaphysis. And the thickened ends are epiphyses. The presence in each epiphysis of the articular surface, covered with articular cartilage, determines the strength of the joint.

Of the tubular is the skeleton of the limbs, in which they are called to perform the functions of levers. Further classification of bones of this type provides for their separation into long and short ones. The first include the shoulder, hip, forearm and lower leg. To the second - metacarpal, metatarsal, phalanx of fingers.

In short (spongy) bones, the shape resembles an irregular cube or polyhedron. They are located in those parts of the skeleton, where a combination of strength and mobility in the junctions is necessary. It's about wrists, tarsus.

Participation in the formation of body cavities and the performance of a protective function are the prerogative of flat (broad) bones, which include the sternum, ribs, pelvis and cranial vault. The muscles are attached to their surfaces, and inside them, like in the tubular case, is the bone marrow.

Short bones in the human wrist allow using a brush to perform a variety of manipulations. And in the toes, feet increase resistance when the person is standing.

Classification of bones provides for the presence and very complex structure of bones mixed species. They are diverse in form and function (arc and spines of the vertebral body).

At airborne in the body there is a cavity lined with a mucous membrane and filled with air. Part of the bones of the skull refers to this species. For example, the frontal, latticed, upper jaw, wedge-shaped.

Classification of bone connections

The whole set of bones forms the passive part of the musculoskeletal system, functioning as a system, in many respects, due to the presence of different types of connection, providing a different degree of mobility.

The joints of the bones are continuous and discontinuous. Also distinguish an intermediate type of compound, which is called symphysis.

Fibrous Compounds

Classification of human bones is important in medicine to prevent damage to the musculoskeletal system. Along with this, the type of tissues to be bonded is also important. This feature makes it possible to isolate fibrous, bone and cartilaginous joints (synchondroses) among continuous joints. Fibrous has a high level of strength and low mobility. Within this group of compounds, syndesmoses, seams and piercing are isolated. Syndemoses include bundles and interosseous membranes.

Types of fibrous joints

Bundles in structure are thick bundles or plates formed by a dense fibrous connective tissue and a significant amount of collagen fibers. Bundle, as a rule, provides connection of two bones and reinforcement of the joint, limiting their movement. Capable of withstanding heavy loads.

With the help of the interosseous membranes, the diaphysis of the tubular bones are connected, and they are the places of attachment of the muscles. The interosseous membranes have holes through which blood vessels and nerves are carried.

One of the varieties of fibrous joints is the seams of the skull, dividing according to the configuration of the joined edges into spongy, scaly and flat. All types of seams have a interlayer layer of connective tissue.

Vkolachivanie is also a special kind of fibrous joint, observed at the junctions of the tooth and bone tissue of the dental alveoli. The tooth and bone wall do not touch. They are separated by a thin plate consisting of connective tissue. It is called periodontium.

Synchondroses and synostoses

Classification of joints of bones provides for the presence of synchondrosis, in which the fastening is carried out with the help of cartilaginous tissue. The main characteristics of synchondrosis are elasticity, strength.

When between the bones the cartilaginous layer is replaced by bone tissue, they lead to a synostosis. Mobility in this case goes to zero, and strength indicators increase.

Joints

The most mobile type of joint is the joints. The characteristic features of these discontinuous fastenings are the presence of special components: articular surfaces, articular cavity, synovial fluid and capsule.

The articular surfaces cover the hyaline cartilage, and the cavity is a slit-like space between the articular surfaces of the bones, surrounded by an articular capsule and containing a significant amount of synovial fluid.

Fractures of bones

A fracture is a complete or partial violation of the integrity of the bone, which arose from an external trauma or in the process of changing the tissue that caused the disease.

The full name of the fracture can be applied when taking into account a number of signs, which are primarily a damaged type, in which the broken bone is localized. In addition, the name of the fracture includes the nature of the causes of its occurrence (traumatic or pathological).

Classification of bone fractures primarily involves their division into congenital and acquired. The presence of congenital fractures is caused by disturbances in intrauterine development and is rare. Among them, the most likely ones are those in which the skull, ribs, collarbone, shoulders and hip suffer. Fractures that have arisen as a result of birth trauma, to intrauterine development of the relationship do not have, therefore, are acquired character.

Acquired fractures can be traumatic and pathological. The former are the consequence of mechanical action and are localized either at the site of this exposure (direct) or outside this zone (indirect). Another group of fractures includes those that are formed due to a lesion of bone tissue by a tumor or other inflammatory or dystrophic processes.

Open and closed fractures

Open fractures are characterized by damage to the skin and mucous membranes in places of traumatic effects, which led to a violation of their integrity. If there is a wound and tissues are crushed, this provokes a risk of infection and the subsequent development of post-traumatic osteomyelitis.

With closed fracture, the integrity of the skin is not disturbed.

Classification of bones, their joints and fractures allows most fully characterize the role of the skeleton in the functioning of the organism as a whole and prevent damage to the musculoskeletal system.