Guide To Understanding Bone Marrow

November 11, 2023

Bone marrow is a spongy substance that fills the insides of the bones. It is responsible for manufacturing blood cells and storing fat. When bone marrow does not function properly, patients could develop low blood counts and other blood-related conditions such as leukemia, aplastic anemia, or myeloproliferative disorders. These disorders could result in symptoms such as fatigue, fever, easy bleeding and bruising, and shortness of breath. Patients with bone marrow issues might also notice they get colds and other infections more often than usual. Doctors may perform blood tests to investigate these symptoms. If the results show abnormalities in blood cell counts, doctors might ask for a bone marrow biopsy to be conducted. Individuals who have bone marrow abnormalities may need to have a bone marrow transplant.

The guide below describes the basic facts about bone marrow and provides information about bone marrow biopsies and donation.

What Is Bone Marrow?

Bone marrow is the semi-solid substance that lines the bones. The two types of bone marrow are yellow bone marrow and red bone marrow. Red bone marrow is responsible for the production of blood cells, and yellow bone marrow helps with fat storage. At birth, babies naturally have a high percentage of red bone marrow. As individuals age, this type of bone marrow is gradually replaced with yellow bone marrow. By the time an individual reaches adulthood, red bone marrow only remains in a few bones of the body, including the ends of the femur and tibia, skull, pelvis, ribs, and ends of the humerus.

Get the details on the function of bone marrow next.

Function Of Bone Marrow

Red bone marrow contains specialized cells called hematopoietic stem cells. These cells develop to form several different types of blood cells, including red blood cells, platelets, and white blood cells. Red blood cells transport oxygen and nutrients around the body, and old red blood cells are also broken down by red bone marrow and the liver and spleen. Platelets promote proper blood clot formation, and white blood cells help combat infection. The newly produced blood cells manufactured by red bone marrow enter the bloodstream through special vessels known as sinusoids. Yellow bone marrow contains fats stored in adipocytes (fat cells) and that can be used as a source of energy for the body. Mesenchymal stem cells are present in yellow bone marrow, and these cells can develop into bone, cartilage, muscle cells, and fat cells. Most of an adult's bones contain yellow bone marrow.

Learn about when bone marrow biopsies are recommended next.

When Bone Marrow Biopsies Are Recommended

After conducting blood tests, doctors may recommend a bone marrow biopsy if the results show certain abnormalities. A bone marrow biopsy can help doctors find out more about the potential cause of the changes in the patient's blood. For example, the biopsy will help medical staff understand whether the patient's issues could be due to a blood disorder or to certain cancers. A bone marrow biopsy might also be performed for patients with cancer to determine how their treatment is affecting their bone marrow. Biopsies are normally performed at a doctor's office or hospital, and they are usually taken from the pelvic bone. Some patients may be given sedatives to help them relax during the procedure. First, the doctor will numb the skin with a local anesthetic. Next, a needle is inserted into the pelvic bone. The needle is attached to a syringe, and the doctor uses this to withdraw a tiny amount of liquid red bone marrow. The procedure takes around ten minutes, and patients who have not been given sedatives will be able to go home fifteen minutes after the procedure is complete. Patients should keep the biopsy site clean, dry, and bandaged for twenty-four hours after the procedure. Some patients experience minor pain for around one week after the biopsy, though this can usually be managed with over-the-counter pain relievers. The results of a bone marrow biopsy are normally available in one to three weeks.

Read about bone marrow donation next.

Bone Marrow Donation

Bone marrow donation can help save the lives of patients with blood cancers and other conditions that require a bone marrow transplant. Individuals who wish to donate bone marrow can join a national registry by submitting a mouth swab. If an individual on the registry is identified as a potential match for a patient in need, they will have blood tests to determine if their bone marrow would be the most appropriate match for the patient. If selected as a donor, patients will undergo a physical examination before the donation procedure. Bone marrow can be donating using surgical and non-surgical methods, and doctors decide which method is best for the recipient's needs. Most bone marrow donors complete the process using peripheral blood stem cell donation. For five days before their donation, donors receive daily injections of filgrastim to increase the number of blood-producing cells in the bloodstream. On the donation day, the donor will have one needle placed in each arm; each needle is connected to a tube that carries blood into a machine. The donor's blood is removed through the first needle. It travels into the machine that collects the blood-forming cells. The rest of the blood is returned to the donor through the second needle. This donation method may take up to eight hours, and ninety percent of donations performed in this way only require one session. The other method for bone marrow donation is a surgical procedure performed under general anesthesia. During the operation, doctors remove liquid bone marrow from the pelvic bone.

Learn about bone marrow diseases next.

Bone Marrow Diseases

Leukemia and aplastic anemia are two of the major types of bone marrow diseases. Patients with these conditions could experience symptoms such as joint pain, bone pain, headaches, pale skin, bleeding gums, as well as easy bruising. Fatigue and shortness of breath could develop, and the lymph nodes, liver, and spleen may become swollen. Individuals might notice more frequent upper respiratory infections, including colds. To diagnose bone marrow diseases, patients will undergo blood tests, and they will also need a bone marrow biopsy. Depending on the particular type of bone marrow disease the patient has, treatment may include chemotherapy, blood transfusions, and antibiotics to treat infections. Patients are treated by specialists, and they receive regular follow-up appointments and frequent blood tests to monitor their progress and response to treatment.

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