Everything you need to know about the human bone marrow. Bone marrow

Between the lines

The word MOZG in Russian historically means wet pulp, loose mass. Probably, earlier people called the pulp inside any bone - in contrast to the hard shell.

The periosteum is a very useful film that surrounds the bone from the outside. The periosteum supplies blood to the surface layers of the bone, and in case of fractures it participates in the formation of "bone callus".

The combination of the simple words "bone" and "brain" creates many complications. Almost no one understands what it is about. Most people are convinced that the bone marrow is either in the head or in the spine, but at the same time they have no idea why it is needed there. Let's figure it out in order.

The “bone” marrow is called due to the fact that it is located in almost all more or less large bones of our body. This red-brown spongy substance is found in the shoulder blades, in the ribs, in the bones of the pelvis, in the base and lid of the skull, in the sternum and other flat and tubular bones.

Red bone marrow is a blood factory. It is within our bones that all blood-forming cells are produced. The work is ongoing, cellular elements are constantly updated. The bone marrow produces stem cells, which in the near future become red blood cells, platelets, and various types of white blood cells. Let's take a closer look at the factory building.

Its “bearing walls” are the periosteum, which allows the bones to grow in thickness, and also protects and strengthens its internal filling. Spongy substance, which lies immediately under the periosteum, acts as a "room" where the medullary beams are formed. Blood stem cells live in their cells: they are a kind of “machines” that stamp their clones around the clock. All these departments are abundantly supplied with blood vessels, which, like a courier service, first deliver everything that is necessary for production to the factory, and then take ready-made cells into the bloodstream.

The bone marrow is the only place in the adult body where hematopoiesis occurs. That is why any changes in it lead to disastrous consequences.

Edward

Thomas

transplantologist

Edward Donnall Thomas (1920 - 2012) - an outstanding American physician, winner of the Nobel Prize in Medicine. In 1959, he was the first in history to transplant bone marrow from a healthy twin sister to a girl in the terminal stage of leukemia. The patient's hematopoiesis recovered, the remission lasted 4 months. It is from this operation that the official countdown of the history of bone marrow transplantation comes.

One of the most important tissues in our body is blood. It is she who is responsible for the supply of oxygen, that is, the nutrition of all cells, organs and systems. Therefore, it is extremely important to replenish the stocks of cells that form blood (erythrocytes, platelets, leukocytes) in time.

The life span of each of the listed cells is quite short and ranges from 5 days (leukocytes) to 100 days (erythrocytes). This entails the need for constant self-renewal of blood. There are organs in the body that perform just this function.

Human hematopoietic organs

The main structures of the body that perform the function of forming new blood cells include the red bone marrow and the spleen. The lymphatic system is also one of the parts for which the bone marrow works. Where is this organ located and what is it, we will consider below.

Location of the bone marrow in the body

The localization of the parts of the body that form blood cells is rather point. The fact is that the main organs of hematopoiesis - the red bone marrow and the spleen - are not the same in their functionality. So, it is the bone marrow that is decisive and basic in this matter, therefore its location, quantity and normal work are very important for any human body.

The main places of localization of the bone marrow are precisely the bones, but not all of them, since the red bone marrow contains only part of the bones, and the rest are yellow.

Structure development

The whole feature of the formation of the bone marrow in humans is as follows:

1. The bone marrow is laid and develops from the very beginning of the embryonic formation of the embryo.
2. At the stage of the embryo and then in the formed fetus, as well as after birth for several years, all the bones of the body are producers (manufacturers) of blood cells and lymphocytes, that is, all of them are formed by the red bone marrow, where the bulk of young undifferentiated cells are located.
3. Over time, it is replaced by yellow in the composition of all tubular large and small bones of the body.

Thus, it is already clear that the bone marrow can be of two forms: red and yellow.

Characteristics of the yellow bone marrow

It is a yellowish fat-like substance formed by cells produced by the lipoid tissue of the body. It does not take any part in the formation of blood or the formation of cellular structures of immunity. In the course of life, it replaces the red brain in many bones, becoming the main filler of the diaphysis of tubular bones in old age. The total mass content in the body is approximately 2.5-3 kg. This is half of the total mass of the bone marrow. The main function is nutrition and giving elasticity to the bones. In addition, with major injuries and injuries, the yellow bone marrow can be temporarily replaced by red to restore the function of normal blood circulation.

The structure of the red bone marrow

Its main constituent part is a large mass of undifferentiated and unspecialized cells, called stem cells. This makes this structure unique and very important for human life. The structure of the bone marrow includes two main tissues: reticular (stroma) and hematopoietic.

The tissue from which all elements of the internal composition of the red brain are formed is called the reticular stroma. It fills the entire internal space of the bones and contains the following elements:

• a large number of blood vessels, giving it a semi-liquid consistency and red color;
• fibroblast cells (producers of fibrin and fibrinogen)

Spleen

In the beginning, we mentioned that not only the bone marrow is important in the formation of blood. Yes, the direct formation of a large mass of its cells and the differentiation of stem cells are characteristic only of him. However, there are other hematopoietic organs that help the bone marrow in this function. The main one is the spleen. Consider its main functions:

• It is the erythrocyte depot of the body, if necessary (large blood loss, trauma, and so on) throws a certain amount of these cells into the total blood mass.
• The spleen is a sentinel, a filterer through which a large mass of blood passes. It neutralizes, eliminates foreign particles, dissolves dead cells. She is an indispensable cleaner of our body.
• Forms monocytes - structures of the heart tissue.

The spleen itself is small and weighs about 150 grams. It is located above the stomach, slightly to the left of it.

Transplantation

Unfortunately, life presents a person with such problems, to get rid of which for a long time was considered generally impossible. For example, until 1968, blood cancer was considered incurable. The same applies to such ailments as aplastic anemia, lymphomas. In these cases, medicine has found the only way out - bone marrow transplantation. The procedure is quite young, complicated due to incomplete knowledge of the consequences and still not always proceeding without complications. But every year such operations are becoming more common and simplified in execution.

Bone marrow transplantation can be of three types:

1. Bone directly.
2. stem cells.
3. Cord fluid (blood).

The choice of type depends on the type of disease. All three varieties are widely used today. The most important problem that specialists face is the selection of a donor for the operation. There are a number of indicators that he must meet in order for the transplant to be successful for both him and the recipient.

Donor selection

Finding a suitable donor for transplantation of homeopoietic structures can be based on several conditions:

• blood type match (not always decisive, but very important);
• the absence of a person's diseases of a severe or chronic nature, as well as infectious diseases;
• the donor has no mental disorders and hereditary ailments.

Most often, relatives are excellent candidates for donation: sisters, brothers, children or parents. But even in this case, guaranteed tissue compatibility is observed only in 25 percent of cases. It is very difficult to determine the ideal source that a healthy bone marrow will give (a photo of how it looks can be seen in the article). Therefore, we have to look for donors among strangers. Such people can be representatives of any nations, countries and races.

Types of bone marrow transplant

There are two main types:

• autologous transplantation - when stem cells are taken from the patient himself in advance and blocked under special conditions before surgery;
• allogeneic transplant - the material is taken from donors, which include all people suitable for the conditions, including relatives.

According to modern data, the world leadership in the donor base is given to Germany and the United States. There are very few donors in Russia, so our patients are transplanted with stem cells from other nations.

The bone marrow is one of the main organs of human hematopoiesis, because only it is responsible for the renewal of blood and stem cells. This special tissue is responsible not only for hematopoiesis (hematopoiesis), but also for the immune system. In the article you will find a detailed description of the bone marrow, its functions and age characteristics, as well as possible diseases of this organ.

What is bone marrow

Bone tissue is an organ that is contained in the internal cavities of large bones. Fibrous tissue contains a large number of immature stem cells, which are very similar in structure to embryonic cells and their other types. For example, those that are responsible for skin regeneration. This structure is responsible for movements that a person does not think about.

stem cells

Stem cells are considered immature, in the process of hematopoiesis, leukocytes, platelets and erythrocytes develop. Red blood cells are responsible for transporting oxygen, while white blood cells fight off bodies that can carry infection, and also play an important role by removing dead cells. Platelets allow blood to clot. They serve to form macrophages, which provide human protection and immunity.

With the help of bone tissue, the blood is cleansed of foreign particles, remnants of dead cells, microbes with the help of its own lymphocytes. Half of the mass of the organ is the blood vessels, where the cells “ripen”, which, with the flow of blood cells, enter the veins of the organ, and then the circulatory system of the whole body. The above cells are also called hematopoietic, they form blood and macrophages.

Where is the bone marrow located in humans?

Next, consider the location and structure of the bone marrow in humans. The organ is located in the bone marrow cavities and the tubular substance of the bones, that is, inside the bones of the human skeleton. The tubular substance is located between the compact substance, which is more commonly known as bone. Localization of the organ - the bones of the sternum, hips, ribs, skull and spine.

What does it look like

Next, you should describe the structure of the organ, what is its appearance. It looks like a small tube inside the bone. Its protection is a barrier to immunological tolerance. The barrier is needed to repel immature and maturing bone marrow cells. Vessels and the central bone marrow cavity are distinguished from the organ. All elements of the structure are protected by a spongy compact substance, osteon.

Structure and types of bone marrow

The organ consists of stroma and hematopoietic elements. There is a certain relationship between them. The rudiments of hematopoiesis are formed from the zones of erythrocytes, leukocytes and platelets. Stem cells produce shaped elements. Outside the bone marrow tissue, mature forms are found. The process is controlled by hematopoietic compounds. The organ is the central and pluripotent peripheral lymphoid organ of the human body. There are such varieties: red and yellow fabrics. Consider the functions of the red bone marrow and the functions of the yellow bone marrow.

red brain

The so-called red bone tissue or RMB is located inside the tubular bones (diaphysis), as well as in flat bones and vertebrae. It is represented by stroma and reticular tissue. The organ is considered a factory that forms other blood elements from stem cells. He takes part in immunopoiesis - the exchange of nutritional values ​​​​(proteins, fats, carbohydrates, minerals), bone formation.

RCM conducts blood cells along the lines of hematopoiesis. Its main function is hematopoiesis (formation, maturation, washing out of blood elements). It is worth noting that the name of the cells is colony-forming elements (CFU) or colony-forming units (CFU). The red brain also includes three components - hematopoietic, vascular and stromal.

yellow bone marrow

Yellow bone tissue or FCM is next to the red one. It performs a reserve function, that is, with severe bleeding, this substance fills the place of rupture with hematopoietic cells. This helps to quickly restore the properties of the blood. It contains a large accumulation of adipose tissue. The mass of FCM is about half of the mass of the entire tissue.

Everything else is KKM. The basis of the organ is loose reticular connective tissue. It contains a collection of cells. Yellow bone tissue fills the empty cavities of the bones. It is considered a reserve for KKM. With blood loss, hematopoietic elements are created that help to recreate the BMC. In the FCM there are areas of myeloid tissue that are characteristic of red.

Cellular composition

Next, we will discuss the cellular composition of bone tissue. It is represented by two groups - stroma and parenchyma. The second group is the cells of the tissue of the internal environment. The reticular stroma includes elements that form the internal tissues of blood vessels, adipose tissue, osteoblasts and fibroblasts. Endothelial cells perform a mechanical and secretory function. They form the environment that is necessary for the normal operation of the stem elements. Growth factors are produced by CM with the help of osteogenic cells. They control hematopoiesis.

The maximum accumulation of these substances can be observed in the endosteum. Next to it, the rapid formation of elements occurs. When performing a biopsy, you can see an increase in red hematopoietic germs. Differentiation of bone growth is determined by the number of fat cells. The endothelial lining is responsible for stimulating hematopoietin and stromal elements. They contribute to the removal of blood flow through the vessels. They are involved in the contraction of the vascular walls.

Bone Marrow Functions

The main function of bone tissue is hematopoiesis. It maintains an optimal level of blood elements. That is, the body replaces dead elements with new ones. Blood supply is carried out by feeding arteries. They form into two sets of capillaries - sinusoidal and feeding. ZhKM is distinguished by the absence of sinusoidal capillaries. Blood is taken from the capillaries by venules, which are collected in the central veins. Nerve fibers along with blood vessels penetrate into the organ itself.

What is the bone marrow responsible for?

The main functions of bone tissue: ensuring all movements of the human body. Everything happens as follows: a thought is formed in our brain, for example, to raise a hand. He transmits this thought to the bone, he quickly accepts it and transmits a signal to the muscles of the hand, which then performs this action. That is, this body is responsible for all reflex actions.

Age features of red bone marrow

The mass of this organ is 2-3 kg. In the embryo, the yolk sac is responsible for hematopoiesis. From the sixth week, this function is performed by the liver, and from the third month - by the spleen. Bone tissue is formed in the second month. From the 12th week, blood vessels and sinusoids develop. Reticular tissue forms around them. From this moment on, the CM functions as a hematopoietic organ.

After birth, the organ occupies the entire bone marrow space. Fat cells appear in the RMC after birth. At the age of 3 years, all the bones of the child are filled with BCM. A year later, it is reborn into fat (yellow). At the age of 25, the yellow brain completely replaces the red brain in tubular and flat bones. In older people, the body acquires a gelatinous consistency.

Bone marrow diseases

• Leukemia is a cancer of the white blood cells. They affect all five types of lymphocytes. A severe illness spreads to the line of elements, which leads to the destruction of the production of other cells. When affected, the patient's leukemia elements do not function normally or do not fight infections.
• Myelodysplastic syndrome or cytopenia is a group of diseases. The nature of this group is the production of pathological abnormal cells of the organ. This leads to bleeding, anemia and infection with various infections. If left untreated, these diseases progress rapidly, leading to acute myeloid leukemia. Myeloproliferative diseases spread throughout the tissue. The organ overproduces mature sprouts of cells that it releases into the circulatory system, in other words, it is hyperplasia.
• Myeloproliferative diseases and others. To determine these diseases in a patient, their further treatment is used puncture of bone tissue. This is a diagnostic method by which doctors obtain a sample of your organ from any bone containing an organ. For this, a special needle is inserted. Then the material is sent for analysis to determine the violation or absence of a certain number of elements.

With the help of the procedure, specialists find out whether a person can be taken as a donor, whether he needs a cell transplant, and whether he is ready for transplantation. If the tests are satisfactory, he is sent for an operation, the course of which the person determines on his own. Before transplantation, a complete examination of the state of the body is carried out: the heart, lungs, kidneys and other organs.

Many are interested in knowing how many ribs a person has. This information is especially useful for those who believe that the number of ribs in men and women is different. In addition, you need to know their structure, possible pathologies, and the functions of the ribs.

The number of ribs in a person before the 16th century was calculated incorrectly. No one could say for sure how many pairs of ribs a person has. This is due to the fact that the Testament indicates the creation of a woman from the rib of a man, which was the subject of many disputes. One of the doctors managed to find out how many ribs men and women have. After receiving the results and announcing them to the world, the scientist was executed, but soon they were convinced that he was right.

How many ribs do men have? Such a question haunted for a long time, but a practical study of human anatomy showed that there are exactly 12 pairs of them. Scientists of that time were amazed, since the number of ribs did not differ by gender. It turned out that the girl also has 24 ribs.

Humans have 12 pairs of ribs

As with all rules, there are exceptions to the equal number of edges rule. Some people have more ribs at birth than others. This phenomenon is called Adam's syndrome. An extra edge is called a rudiment, since it does not carry any function. Statistics claim that the syndrome is more often manifested in the beautiful half of humanity, but the pathology does not bypass the male population either.

Structure

The ribs look like protruding plates with a thickness of up to 5 mm.

The rib consists of cartilage and bone parts. Part of the bone consists of spongy tissue, it is divided into the neck, body and head. Below the body is a furrow. Vessels and nerve fibers pass through it, thanks to which the ribs, muscles and organs receive nutrition. With the help of cartilage, the body of the rib is attached in front to the sternum.

The first 20 ribs are tightly connected to each other, forming a ring to protect the organs. Of the 20 ribs, 14 are attached specifically to the sternum, the rest 6 are attached to the cartilage of the ribs, are higher and are false, the rest are called free. The last pair of ribs are attached only to muscle tissue. The numbering is from the top.

The ribs go around the internal organs of the body area, allowing them to be closed from external and internal influences or damage. It's the same factor for everyone.

At birth, a baby's ribs are mostly cartilage. Cartilage is a fragile tissue, but over time, a child's ribs become hard. The baby is extremely vulnerable to injuries of organs and ribs, therefore, extremely careful handling of the newborn is required, since the bone tissue has already formed in an adult, but not in a baby.

What function do

A certain arrangement of the ribs allows all organs to remain in place. Thanks to the function of the frame, the heart will not be able to move to the other side, and the lungs will not fall off. Muscle tissue is attached to the ribs. In addition, they protect vital organs from damage. The protective function of the ribs works when exposed to the chest.

The sternum contains red bone marrow.

Possible pathologies

Fractures are the most common rib problem. They arise as a result of mechanical action on the human chest. This impact can be a collision, impact, pressure with great force. Due to injury to this area, internal organs may be affected. High risk of damage to blood vessels and nerves that are located in the ribs. Due to the fact that there is a large bend in the lateral part, this area is the most prone to injury.

Injuries can be distinguished by the presence of displacement, fragments from the bone, or the appearance of a crack. No matter how severe the injury, it is important to consider that the primary protective function of the ribs is now less effective, as the damaged rib cage is unable to fully protect the internal organs.

Most often, people over 55 years of age suffer from such injuries, when calcium in the body gradually becomes less. Sometimes younger people suffer from such cases. This is due to a lack or non-absorption of calcium, the fragility of bone tissue is caused by the presence of pathological processes in the body.

Osteoporosis is not the only disease that can affect the ribs. Since they contain red bone marrow, it can suffer from leukemia or multiple myeloma. If any part of the chest is affected by a tumor, then it is able to grow between the ribs, reducing their strength.

Diagnostics

You can diagnose deviations by contacting a doctor. The first signs of injury are pain in the chest, which sometimes radiates to the cervical region, when inhaling, exhaling, coughing, etc. The most dangerous sign of a compound fracture is bone that sticks out strongly under the skin or from the wound. Less often, redness or bruising appears as a sign of a simple fracture, sometimes abrasions occur at the site of injury.

This is worth paying attention to if there was a fall, impact or other impact on this area the day before. The doctor during the session examines the patient, can make palpation. Then an X-ray procedure is performed. The picture will clearly show which part of the chest the injury occurred, how many ribs were hurt, how serious the damage is. A puncture or ultrasound may be required.

Treatment of diseases

A fracture of any severity requires treatment in a hospital. If the injury is not severe, then fixation is not required. It is not used because the risk of developing pneumonia increases. Fixation of the chest is necessary if the injury is extremely severe, multiple.

It is believed that for a simple form of fracture to recover, it takes about 4 weeks. This indicator may vary depending on the characteristics of the human body. Effort is forbidden. Complicated fractures take longer to heal. It is extremely rare that an operation is required that is performed through an incision. It is resorted to if a displacement occurs during a fracture or a fragment from a rib gets into the chest cavity.

The tumor requires surgery. In osteoporosis, drugs are prescribed that prevent the leaching of calcium and help it to be absorbed in the body.

Each disease requires an individual approach and timely treatment, then there will be no complications.

Complications

The lack of timely treatment negatively affects the general condition of a person. Complications are extremely difficult to correct. Human ribs can damage internal organs if the fracture is not detected in time. With improper fusion of the rib, its strong protrusion is noticeable.

Disease prevention

The human ribs are not considered a complex part of the body, but they need support, like all other organs. To avoid problems with bones, it is recommended to strengthen weak immunity, take multivitamins, calcium, spend more time in the sun, play sports. Increased immunity contributes to the use of fruits, vegetables, fish, dairy products.

The question is about how many ribs does a person have, as a rule, puzzles people who have begun to study anatomy - this is a fairly simple fact.

The ribs in the human skeleton are arranged in pairs. The number of costal bones is the same for men and women.

In total, a person has 24 ribs, 12 pairs of ribs. But it is worth noting the fact that in the process of the evolutionary formation of the human skeleton, earlier, there was another pair of ribs, but in the process of the development of man and primitive society, it ceased to form and exists only in the form of rudimentary rudiments.

All twelve pairs of ribs have the same structure: in the rib there is a bone part (the longest component of the rib), costal cartilage and two tips - anterior (facing the sternum) and posterior (facing the spinal column).

The costal bone consists of a head, neck and body. The head is located at the posterior end of the rib. The body of the rib is the longest curved part that forms the angle of the rib. The neck is the narrowest and most rounded fragment of the costal structure.

The functionality of the costal bones (how many ribs a person has)

It's worth knowing:

• Ribs protect internal organs from mechanical damage. The ribs form a protective bone frame and protect the insides not only from shock loads, but also from displacement with concomitant compression;
• The ribs serve as a framework for attaching many muscles, including the diaphragm necessary for breathing and speech;
• Also, the rib cage reduces the load on the spinal column and is the site of localization of the red bone marrow - the main hematopoietic organ in the human body;
• The ribs are attached to the spinal column with the help of joints and adjoin the sternum due to synarthrosis. The thorax is covered by the pleural membrane, which acts as a lubricant for the lungs.

The integrity of the ribs and chest, or why is it worth protecting the ribs?

Speaking of ribs, it is necessary to note the risks to which a person can expose them. Due to accidents at work, leisure and in everyday life, such a pathology as a fracture of a rib or rib pair is common.

1. A fracture can cause collateral damage to internal organs, such as stab and cut wounds. Fragments of bone tissue can get into the cavities of the internal organs.
2. Elderly people are more prone to fractures of the costal processes due to mechanical damage: after all, in old age, the strength of bone tissue decreases, and the elasticity of the ribs decreases.
3. Chips of bone tissue can damage the pleura and cause pneumothorax - a serious deviation in the respiratory system caused by air entering between the pleural sheets.
4. Violation of the tightness of the lungs due to injury to the ribs can lead to hemothorax - the ingress of blood particles into the lung cavity.
5. In addition to mechanical pathologies, the ribs are subject to irreversible changes due to age or concomitant diseases.
6. In adulthood, the ribs are affected by osteoporosis. The calcium concentration in the bones drops to critical values ​​and the ribs become very fragile. With cancer, the ribs can serve as a site for the localization of the tumor.
7. If the tumor is not stopped in a timely manner, then it can affect adjacent organs. Despite the fact that the ribs are formations of bone tissue, they can be subject to inflammatory phenomena that occur due to tuberculosis or leukemia.

However, not only accidents can damage the ribs, but also crazy new trends. Modern cosmetology has recently been practicing a wild, in the understanding of the majority, way of giving the waist the desired shape and proportions.

Some women undergo an endoscopic resection of the ribs - in other words, they remove the lower pair of costal bones. Indeed, this procedure improves the appearance, but can lead to a deviation in the functioning of internal organs and become a catalyst for irreversible morphological changes in the body.