Bone marrow

Definition

Bone marrow is a soft, spongy tissue located in the center of bones, responsible for producing blood cells, including red blood cells, white blood cells, and platelets. It serves as a primary source of hematopoietic stem cells, which are vital for the body’s ability to replenish its blood supply and support the immune system.

5 Must Know Facts For Your Next Test

1. Bone marrow can be classified into two types: red marrow, which is involved in blood cell production, and yellow marrow, which primarily stores fat and can be converted into red marrow if needed.
2. In adults, red bone marrow is mainly found in flat bones like the pelvis, sternum, and ribs, while yellow marrow is prevalent in long bones.
3. Bone marrow contains a variety of stem cells beyond hematopoietic stem cells, including mesenchymal stem cells, which can differentiate into bone, cartilage, and fat cells.
4. Bone marrow transplant procedures can be used to treat diseases like leukemia and lymphoma by replacing damaged or diseased bone marrow with healthy stem cells.
5. The production of blood cells in bone marrow is regulated by various growth factors and hormones, ensuring that the body maintains appropriate levels of different blood cell types.

Review Questions

• How do hematopoietic stem cells in bone marrow contribute to maintaining the body's blood supply?
  • Hematopoietic stem cells located in the bone marrow are crucial for producing all types of blood cells. They undergo differentiation to form red blood cells that carry oxygen, white blood cells that fight infection, and platelets that help with clotting. This continuous production is essential for maintaining an adequate blood supply and supporting various physiological functions.
• What role do stromal cells play in the function of bone marrow regarding stem cell regulation?
  • Stromal cells in the bone marrow create a specialized microenvironment that supports hematopoietic stem cells. They secrete growth factors and cytokines that regulate the survival, proliferation, and differentiation of these stem cells. This interaction is essential for ensuring that the hematopoietic system functions effectively and responds appropriately to the body's needs.
• Evaluate the implications of bone marrow aplasia on overall health and potential treatment options available.
  • Bone marrow aplasia leads to a significant reduction in blood cell production, resulting in conditions like anemia, increased susceptibility to infections due to low white blood cell counts, and bleeding disorders from insufficient platelets. Treatment options may include immunosuppressive therapy to allow recovery of bone marrow function or more severe cases may require a bone marrow transplant to restore healthy hematopoiesis. The choice of treatment will depend on the underlying cause of the aplasia and the patient's overall health status.

Related terms

hematopoietic stem cells: Stem cells found in bone marrow that have the ability to develop into various types of blood cells, playing a crucial role in blood formation.

stromal cells: Supportive cells in the bone marrow that provide a microenvironment for hematopoietic stem cells and help regulate their growth and differentiation.

aplasia: A condition where bone marrow fails to produce sufficient blood cells, leading to serious health issues such as anemia and increased risk of infections.