Bone marrow

Definition

Bone marrow is a soft, spongy tissue found in the center of bones, primarily responsible for producing blood cells, including red blood cells, white blood cells, and platelets. It plays a vital role in the immune system by generating lymphocytes, which are crucial for adaptive immunity, helping the body recognize and remember pathogens.

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.
2. In adults, hematopoiesis mainly occurs in the pelvis, ribs, sternum, and vertebrae, while in children it takes place throughout most bones.
3. Bone marrow produces about 500 billion blood cells each day, including millions of red blood cells to replace those lost to wear and tear.
4. Bone marrow also contains stromal cells that support the growth and differentiation of blood cells.
5. Diseases affecting bone marrow, such as leukemia or aplastic anemia, can severely impact the body's ability to produce sufficient blood cells and fight infections.

Review Questions

• How does bone marrow contribute to adaptive immunity through its production of specific blood cells?
  • Bone marrow plays a crucial role in adaptive immunity by producing lymphocytes, particularly B cells and T cells. B cells are responsible for antibody production while T cells help in directly killing infected cells or coordinating the immune response. These lymphocytes then migrate to lymphoid organs where they encounter pathogens and develop a targeted immune response. The ability of these cells to remember past infections forms the basis of adaptive immunity.
• Analyze how diseases of the bone marrow can affect overall immune function and hematopoiesis.
  • Diseases such as leukemia or aplastic anemia severely impair bone marrow function. In leukemia, abnormal proliferation of white blood cells disrupts normal hematopoiesis, leading to insufficient production of healthy red and white blood cells. Aplastic anemia results in the failure of bone marrow to produce adequate blood cells. Both conditions compromise the immune system's ability to respond to infections effectively, making patients more susceptible to illnesses.
• Evaluate the significance of stem cell research focused on bone marrow and its implications for treating diseases related to blood cell production.
  • Stem cell research targeting bone marrow holds significant potential for treating various blood disorders. By understanding how to manipulate stem cells, researchers can develop therapies that could regenerate healthy bone marrow function in conditions like leukemia or aplastic anemia. This research also opens avenues for creating personalized medicine approaches where patients could receive treatments derived from their own stem cells, minimizing rejection risks and improving recovery outcomes.

Related terms

hematopoiesis: The process by which all blood cells are produced from stem cells in the bone marrow.

lymphocytes:

A type of white blood cell that is essential for the adaptive immune response, including B cells and T cells.

stem cells:

Undifferentiated cells found in the bone marrow that have the potential to develop into various types of blood cells.