Basic Types of Human Bone Connections: Scheme and Table

In the body of an adult, 206 bones, while in a newborn child their number reaches 350, then in the process of life they fuse. Most of them are paired, 33-34 remain unpaired. Bones are actuated with the help of muscles and tendons. Bones form a skeleton: the spine, upper and lower limbs and the skull. In order to connect them among themselves, there are different types of connection of bones.

Functions of the human skeleton

The main functions of the skeleton are the support for internal organs, as well as providing a person with the ability to move in space. In order to successfully carry them out, the bones must possess, on the one hand, strength, on the other - elasticity and ease. Both of these functions are provided, among other things, thanks to the different types of connection of bones.

In addition to support, the bones are a protection for internal organs, as well as blood-forming organs (due to a spongy substance containing red bone marrow).

Types of connection of bones

In the human body there are different types of bones: flat, tubular, mixed, short and long. There are different types of connection of human bones that provide the skeleton with the ability to perform its functions. There is no single classification of the types of articulations of bones. Some sources divide the bones into two, others into three types. According to the first version, these are mobile and fixed connections. The third type, which is not all referred to as independent, are semi-mobile connections. The most obvious is the connection types of the bones table. The types of mobile connections are shown below.

Continuous, or fixed connections

Continuous connections of bones are those that do not have a cavity and are immovable. Determine the fixed connection can be even in appearance - the closed surfaces have roughness, notch, that is, they are uneven.

Both surfaces are joined by means of connective tissue.

An example is the joints of the skull bones that are formed with the help of the bone seam.

Other fixed joints fuse with each other, that is, the cartilaginous tissue is replaced by the bone, which gives this department a special strength. Such types of connection of bones can be found in the spine, in the sacral region, where the coccyx is five intergrown coccygeal vertebrae.

Means of preserving the immobility of bone connections

As can be seen from the examples, immobility is provided in different ways, therefore, there are basic types of bone connection in a continuous way:

• Type of connection through connective tissue of dense fibrous type (bones near joints).
• Syndesmosis, which is a connection using connective tissue (for example, the bones of the forearm).
• Synchondroses - with the help of cartilage (connection of vertebrae in the spine).
• Synostosis, that is, bone joints (skull bones, coccyx).

The first and second points are the types of connection of human bones with the help of various types of connective tissue, therefore they are referred to as fibrotic compounds.

Syndesmoses perform their function with the help of ligaments, which additionally strengthen the joints of the bones.

The concept of bundles

They are strands formed by bundles of elastic and collagen fibers. Depending on which type prevails in a particular bunch, they are divided into elastic and collagen.

Depending on the required amplitude, fluctuations in the bones of the ligament can be short or long.

There is also a classification of cords by their belonging to the joints - articular and extraarticular.

Bundles are needed not only to connect the bones, they have several other important functions:

• Frame role, because the ligaments begin muscles.
• Hold and fix among themselves various parts of bones or parts of the body (sacro-ligamentous ligament).
• With the help of ligaments, another anatomical structure is formed (for example, a vault or niche for the passage of nerves and vessels).

Types of connective tissue connections

In addition to ligaments, bone joints can be formed by a connective tissue and called membranes. Their difference lies in the fact that the membrane fills the space between the bones, and the distance between them is quite large. Most often, membranes consist of elastic fibers. However, in their functions they perform the same role with bundles.

The next type of connective tissue connection between the bones is the fontanel. This type can be observed in newborns and children up to a year, until the fontanelles are overgrown. This formation, which has few elastic fibers and is represented mainly by an intermediate substance. Such a connection allows the bones of the skull to change the configuration for passage through the birth canal.

The seam can be found by studying, for example, the connections of the bones of the skull. Seams can be of various shapes, having similar names - dentate, flat, scaly.

Vlekachivaniya connect the alveolar processes with teeth. The connective tissue in this area is called "periodontium." It has good blood supply and nervous innervation due to blood vessels and nerve fibers in the intermediate substance. The periodontal structure includes also elastic and collagen fibers.

Movable joints

The following types of connection of bones are mobile. These include the joints (diarthrosis). These kinds of connection of bones are called discontinuous because of the fact that there is always a cavity between their surfaces. In order to provide mobility, they consist of articular surfaces, an articular bag and a cavity.

Components

The articular surfaces are those parts of the bones that abut each other in the joint bag. They are covered with cartilage, called articular.

In order for such a connection to function properly during the life of a person, there is a cavity in the bag filled with a liquid that lubricates the clamping surfaces. In addition, the liquid performs amortization functions, providing endurance to the joints, and provides the necessary nutrition to the articular cartilage.

The joint bag protects the joint surfaces from damage, to perform this function it consists of several layers: fibrous and synovial. The internal synovial membrane provides a rich blood supply.

In addition to the obligatory, in the joint there may be additional elements: cartilages and ligaments, synovial bags, sesamoid bones and synovial folds.

Classification of joints by various parameters

Joints can be of different shapes: globular, ellipsoidal, flat, saddle, etc. In accordance with it, the same joints are also distinguished. Distinguish the classification and the projection of motion - uniaxial, biaxial and multiaxial. To uniaxial include block and cylindrical joints (for example, ankle, interphalangeal). Biaxial joints are ellipsoidal or saddle (wrist-metacarpal, metacarpal). To multiaxial belong joints, having a globular shape - humeral, hip.

According to the shape of the joint, one can assume in what directions its movement will be realized. For example, the globular carries out movements in different directions, that is, it is triaxial.

The device distinguishes between simple and complex joints. Simple consists of two bones, complex - of three or more.

Joints can perform the following movements: flexion-extension, reduction-spinning, rotation (inside and out, as well as circular).

Semi-mobile bone joints

Many do not consider this group to be independent. Semi-mobile compounds are those that are formed by cartilage, that is, on the one hand, are not mobile, like joints, but have a certain degree of flexibility.

The type of connection with cartilage is considered as one of the types of fixed joint - synchondrosis, which is not semi-mobile, as many people think. There is a difference between synchondrosis and semi-mobile compounds: in the latter there is a small cavity, due to which mobility is provided.

Semicontinuous compounds are also called symphysis. Under certain conditions, they may somewhat diverge. So, pubic symphysis allows in childbirth to ensure the passage of the fetus on the birth canal.

Instead of concluding

So, we got acquainted with the basic types of connections of human bones, their features and the functions they perform.

When considering such a topic as the types of connection of human bones, the table and the diagram will be the best assistants, since they give an opportunity to visually see and understand the classification.