Bone Marrow Flashcards

Study bone marrow anatomy, including red and yellow marrow, hematopoietic tissue, cellular organization, blood supply, and immune functions.

Card 1 of 30Question

What is bone marrow?

A specialized soft tissue occupying the medullary cavities and spaces between trabeculae of bones.

In This Section

1. What is bone marrow?

A specialized soft tissue occupying the medullary cavities and spaces between trabeculae of bones.

2. How is bone marrow classified within the lymphatic system?

As a primary lymphatic organ.

3. What are the two principal types of bone marrow?

Red bone marrow and yellow bone marrow.

4. What is the primary function of red bone marrow?

Hematopoiesis, the production of blood cells.

5. What is the principal cellular component of yellow bone marrow?

Adipocytes, which store lipids.

6. Where is red bone marrow predominantly located in healthy adults?

In the vertebrae, ribs, sternum, pelvis, skull, and proximal ends of the humerus and femur.

7. Where is yellow bone marrow predominantly found in adult long bones?

Within the medullary cavities of the diaphyses.

8. How does bone marrow distribution differ between newborns and adults?

Newborns have predominantly red marrow, while adults have increased yellow marrow and more restricted red marrow distribution.

9. What is marrow conversion?

The progressive replacement of hematopoietic red marrow by fatty yellow marrow during growth and aging.

10. What is bone marrow reconversion?

An increase in hematopoietic red marrow within previously fatty marrow regions during heightened blood cell production demands.

11. Which cells give rise to all mature blood cell lineages?

Hematopoietic stem cells.

12. What are the two major progenitor pathways of hematopoietic differentiation?

Myeloid and lymphoid progenitor pathways.

13. Which mature blood cells develop through the myeloid lineage?

Erythrocytes, platelets, granulocytes, and monocytes.

14. Which major immune cell types develop through the lymphoid lineage?

B lymphocytes, T lymphocytes, and natural killer cells.

15. Which lymphocytes undergo antigen-independent maturation in bone marrow?

B lymphocytes.

16. Where do T lymphocyte precursors complete their maturation?

In the thymus after originating from hematopoietic progenitors in bone marrow.

17. What are the principal structural components of red bone marrow?

Hematopoietic cells, a supporting stromal network, adipocytes, and vascular sinusoids.

18. What is the function of the bone marrow stroma?

To provide structural support and a specialized microenvironment for hematopoietic cell development.

19. What are bone marrow sinusoids?

Specialized thin-walled vascular channels that allow mature blood cells to enter the circulation.

20. Which large bone marrow cells produce platelets?

Megakaryocytes.

21. What are erythroblastic islands in red bone marrow?

Clusters of developing erythroid cells organized around a central macrophage.

22. Which arteries supply the medullary cavity of a typical long bone?

Nutrient arteries entering through nutrient foramina, supplemented by metaphyseal and epiphyseal vessels.

23. How does venous blood leave the bone marrow?

Through marrow sinusoids that drain into collecting veins and ultimately exit through osseous venous channels.

24. Which bone is commonly used for bone marrow aspiration in adults?

The posterior iliac crest.

25. Why is the posterior iliac crest preferred for many bone marrow biopsies?

It provides accessible hematopoietic marrow and permits relatively safe sampling of marrow and trabecular bone.

26. What is the difference between bone marrow aspiration and trephine biopsy?

Aspiration obtains liquid marrow for cellular examination, while trephine biopsy obtains a tissue core preserving marrow architecture.

27. What is aplastic anemia?

Bone marrow failure characterized by reduced hematopoietic cell production and decreased circulating blood cells.

28. What is the anatomical significance of bone marrow in leukemia?

Leukemic cells can proliferate within marrow spaces and disrupt normal hematopoiesis.

29. What is extramedullary hematopoiesis?

Blood cell production outside bone marrow, commonly involving the spleen or liver in certain diseases.

30. What is the role of bone marrow in hematopoietic stem cell transplantation?

Transplanted stem cells can establish hematopoiesis in marrow and regenerate blood and immune cell populations.