Spongy bones. Scheme of spongy bone. Structure of a spongy bone

The human skeleton consists of more than 200 bones.All of them perform a specific function, generally creating support for the external and internal organs. Depending on the load and role in the body, there are several varieties of them.

Structure of bones

In dry form, human bone 1/3 consists oforganic matter - ostein protein. It provides its flexibility and resilience. 2/3 is inorganic calcium salts, due to which their strength is achieved.

The outer shell is the so-calledcompact matter. These are dense scales of bony tissue. Their densest layer can be observed in the center of the tubular bones. To their edges, the compact substance becomes thinner.

Depending on the type of bones, their internal partmay consist of either spongy matter or white bone marrow, or it may be filled with air. Spongy bones, in addition, also have a red bone marrow.

At the ends, nerves and blood vessels enter the bone, which connect it with the entire body and provide nourishment, growth and recovery.

Types of bones of the human body

According to the structure of the bone is divided into spongy,tubular and pneumatic. Tubular called still long. They are present in the skeleton of the limbs and are responsible for their movement. These bones consist of a compact substance and a cavity filled with yellow bone marrow. At the ends they have a little spongy substance filled with red bone marrow.

Human spongy bones are completely made up ofspongy substance with a red bone marrow inside, they are covered with a compact substance. They form cavities (chest, cranial) and serve as a support in places with the greatest load (spine, phalanges of the fingers).

Pneumatic bones have a special structure: inside a compact substance there is a cavity, served by epithelium and filled with air. As an example, you can call the skeleton of the upper jaw.

Spongy bones: detailed scheme

As already noted, at its core, the structurecancellous bone is almost the same as others. This is a cavity formed by a compact substance and filled with spongy. By origin, they are different. The bones of the ribs, for example, are formed from cartilage tissue, and the skull caps are made from connective tissue.

Spongy substance consists of a variety of thinbone septa directed in accordance with the movement of substances in the bone. This structure allows you to achieve greater strength from the bones. They are less likely to break and crack.

At the edges of the bones there is cartilage tissue, through which nutrients enter and end nerves.

The spongy cavities are filled with red bone marrow, which is responsible for the formation of red blood cells. Such a spongy bone scheme allows it to perform several very important functions at once.

Varieties

In the structure of the human skeleton, the spongy bones have a quantitative advantage. Therefore, scientists distinguish several of their varieties.

There are flat and voluminous bones.Flat form the lid of the skull and pelvic cavity. This includes the shoulder blades. Volumetric represented by ribs and phalanges of the fingers. The vertebrae are referred to as a mixed type, since their body consists of a voluminous tubular bone, and the process is flat.

In size, it is customary to isolate long and short spongy bones. One of the longest edges are considered. The short bones belong to the phalanges of the fingers and toes.

A unique bone can be called a scapula. It is attached to the body only with connective tissue, while most bones are connected by joints.

Sponge Bone Functions

Первая и главная функция, которую выполняют spongy bones are the anchor. They create the basic framework of the human skeleton. The vertebrae form the spine, supporting the entire body in an upright position. The foot bones hold the entire body weight.

The second function is protective. Human spongy bones create and surround cavities, protecting their contents from external damage. It is a skull cap, ribs and pelvic bones.

Motor function is performed by the bones of the phalanges of the toes and hands.

With a metabolic disorder, bones can become very fragile or extremely strong. In both cases, it is dangerous for normal human life.

The internal filling of the bones - the bone marrow - plays a major role in the formation of blood.

Red bone marrow value

In the human body, the circuit of the cancellous boneimplies the obligatory presence of red bone marrow in it. This substance is so important for vital activity that it is present even in tubular bones, but in smaller quantities.

In childhood, the spongy and tubular bones are equally filled with this substance, but with age, the tubular cavities are gradually filled with fatty yellow bone marrow.

The main task of the red bone marrow is synthesisred blood cells. As you know, these cells do not have a nucleus and cannot divide themselves. In the spongy substance they ripen and enter the bloodstream during metabolism in the bones.

Red bone malfunctionThe brain entails diseases such as anemia and types of blood cancer. Often, drug treatment is not effective and you have to resort to transplantation of the red brain.

This substance is very sensitive to radiation.radiation. Therefore, many people affected by it have precisely various forms of blood cancer. The same property is used in transplantation, when you need to kill infected bone marrow cells.

Possible damage

By its nature, the structure of the cancellous bone allows it to be quite resistant to mechanical damage. But often there are cases when the integrity of the bone is broken.

Compression fractures are characterized by compression.bones due to strong effects on her. Vertebrae are very susceptible to this type of damage. You can get injured during a bad landing on your feet or falling. The danger of a fracture is that the vertebra ceases to protect the spinal cord, which can lead to its damage.

Поскольку большинство длинных губчатых костей have a curved shape, they can give cracks during a strong blow to hard objects. Such damage is relatively safe. With timely medical care, the cracks heal rather quickly.

Can spongy bones and break.In some cases, injuries of this kind are practically not dangerous. If there was no bias, they are restored fairly quickly. The danger consists of those bones, which at a fracture can shift and pierce the vital organs. In this case, a relatively harmless fracture becomes the cause of disability and death.

Bones and age changes

Like all other human organs, the spongy bones are subject to age-related changes. At birth, some of the future bones are either not yet fully developed or have not been formed from cartilage and connective tissue.

С годами костям свойственно «высыхать».This means that in their composition the amount of organic substances becomes less, while mineral substances replace them. The bones become fragile and recover longer after damage.

The amount of bone marrow is also gradually decreasing. Therefore, older people are prone to anemia.