The bone marrow is the soft tissue that fills the inside of the bones. It plays an extremely important role in the body - it produces blood. What are the types of bone marrow, how does it get sick, and what are the treatments for this tissue?

Bone marrowis a soft and even gelatinous tissue with a lot of blood supply to it, which is located inside the marrow cavities of long bones, as well as in small pits within the spongy bone. It is made of reticular tissue and capillaries with a special structure - thin walls and sinus widenings. It creates a kind of network in which cells such as erythroblasts, fat cells, megakaryocytes, myelocytes, osteoblasts and osteoclasts hang.

Bone marrow is formed at the end of fetal life. Newborns and children up to the age of 6-7 have all the red marrow. It fills almost all bones (it is related to the enormous needs of a rapidly growing and developing organism), while with age it begins to transform into yellow marrow, and the red one gradually gets smaller.

In an adult, red marrow is found only in flat bones: sternum, ribs, vertebral bodies, skull bones, shoulder blades, pelvic bones and epiphyses of long bones and constitutes only about 50% of the total marrow. In an adult, it weighs about 2.5 - 4 kg, which is about 5% of the weight of the whole body.

Bone marrow - types

Bone marrow comes in two forms:

  • Red bone marrow- is a place of production and continuous renewal of blood cells. It produces: erythrocytes (red blood cells that contain hemoglobin and carry oxygen to muscles, including the heart muscle, brain, liver, kidneys and other organs), leukocytes (white blood cells, responsible for our immunity, and therefore for fighting germs, such as viruses, bacteria, fungi, parasites, toxins, and the recognition and destruction of abnormal cells in the body, including cancer cells), platelets (involved in the clotting process).
  • Yellow bone marrow- consists mainly of fat cells, does not produce blood cells. But in cases of disorders, such as anemia, it can transform into red marrow.

Bone marrow - Features

  1. Production of blood elements (as above).
  2. In the marrowthere are stem cells that ensure that our blood has the right composition throughout our lives. They cyclically recreate blood cells and produce cells of the immune system, B lymphocytes, which are involved in the body's defense reaction against pathogens.
  3. Disposal of old, damaged, not working properly.
  4. Collecting iron from damaged blood cells.

What is bone marrow testing?

If a bone marrow disease is suspected, the patient must undergo tests such as a myelogram, i.e. microscopic examination of a bone marrow smear, or cytochemical tests. If the marrow needs to be collected for testing, it is done in one of two ways:

  • aspiration biopsy - using a special syringe, the doctor inserts a needle through the skin into the bone and takes a small amount of bone marrow
  • trepanobiopsy - a procedure involving the excision of a bone fragment together with the marrow for histopathological examination

Bone marrow diseases

Bone marrow diseases can be divided into:

  • deficiency disorders - anemia caused by a deficiency of vitamin B12, folic acid, iron;
  • failure disorders - aplastic anemia, myelofibrosis, thrombocytopenia, peripheral blood granulocytes deficiency;
  • neoplastic disorders - leukemias.

Bone marrow transplant

A damaged bone marrow, e.g. caused by cancer, is life-threatening. You can rebuild it by introducing new stem cells into the body, which will be produced by blood cells. Either bone marrow or stem cells from peripheral or umbilical cord blood are transplanted.

There are autologous and allogeneic transplants.

  • Autologous transplant- the donor is the patient himself. The procedure consists in taking the marrow, cleaning it and reintroducing it into the body. This type of transplant is used after the highly toxic cancer treatment with drugs that destroy the bone marrow.
  • Allograft- the donor is a person (preferably from the family, sister or brother), tissue compatible with the recipient. Transplantation is performed in the case of lymphocytic leukemia and acute non-lymphocytic leukemia, in severe aplastic anemia, in severe combined immunodeficiencies.

Category:

Cardiology