The document discusses the composition and functions of bone marrow, highlighting its roles in hematopoiesis and as a source of pluripotent stem cells. It explains the two types of bone marrow: red marrow, which produces blood cells, and yellow marrow, which stores fat. Additionally, the document covers the histology of bone marrow and provides an overview of jaundice, detailing its definition and types.

1. BY
Dr. ARUN CHANDRAN R
COMPOSITION & FUNCTIONS OF
BONE MARROW

2. INTRODUCTION
• Also called as Myeloid tissue.
• Constitutes around 4% of the total body mass of humans.
• A highly vascular, soft and flexible connective tissue within
medullary cavities of bones which serve as the primary site of
hematopoiesis.
• In adult humans , bone marrow is primarily located in the center
of most bones ( ribs, vertebrae, sternum and bones of the pelvis. )
• Primary source of pluripotent stem cells that give rise to all
hemopoietic cells.

4. There are two types of bone marrow.
•They are medulla ossium rubra (red marrow), which consists
mainly of hematopoietic tissue, and
• Medulla ossium flava (yellow marrow), which is mainly made up
of fat cells.
•Red blood cells, platelets and most white blood cells arise in red
marrow.
•Both types of bone marrow contain numerous blood vessels and
capillaries.

8. •In adults red bone marrow is found only in the vertebrae, hips,
sternum, ribs, skull and at the ends of the long bones of the arms
ad leg.
•Red Bone Marrow consists of a delicate, highly vascular fibrous
tissue containing stem cells, which differentiate into various
blood cells.
•Stem cells become precursors or blast cells.
•Produce about 6 billion cells per kg of body weight.

9. HISTOLOGY OF BONE MARROW:
•Consists of stromal & Hemopoietic tissue
STROMA:
Consists of
1. A network of sinuses , arising from cortical capillaries at the
endosteum
2. Adipocytes (fibroblasts): Can undergo lipogenesis and get
transformed into fat cells.
3. Extra cellular Matrix
Stromal cells are the source of growth factors & cytokines.

10. HISTOLOGY OF BONE MARROW:
•Structure of bone marrow constitutes of hemopoietic tissue
islands and adipose tissues surrounded by vascular sinuses
within a meshwork of trabecular bone.

11. HISTOLOGY OF BONE MARROW:

12. HISTOLOGY OF BONE MARROW:
The bone marrow is composed of both cellular and non-cellular
components and structurally be divided into
vascular and non-vascular regions.
The non-vascular section of bone marrow is composed of
 Hemopoietic cells of various lineages and maturity, (packed
between fat cells, thin bands of bony tissue , collagen fibers,
fibroblasts and dendritic cells.)
This is where hematopoiesis takes place.

13. HISTOLOGY OF BONE MARROW:
•The vascular section contains blood vessels that supply
the bone with nutrients and transport blood stem cells and
formed mature blood cells away into circulation.
• Hemopoietic cells cluster around the vascular sinuses where
they mature, before they eventually are discharged into the
blood.
•Lymphocytes are found surrounding the small radial arteries,
whereas most immature myeloid precursors are found deep in the
parenchyma.

14. FUNCTIONS OF BONE MARROW:
1. Red bone marrow is involved in Haemopoeisis
2. Bone marrow gives rise to all of the lymphoid cells that
migrate to the thymus and mature into T cells.
3. B cells mature in the bone marrow.
4. Platelets which are formed in the bone marrow.
5. Yellow marrow is involved in the storage of fat.
6. Contributes to the destruction of RBC, along with liver and
spleen.
7. Yellow marrow can be converted into red marrow under
conditions like severe blood loss or fever.

16. BY
Dr. ARUN CHANDRAN R
JAUNDICE

17. DEFINITION:
• Condition characterized by yellow discoloration of the skin,
mucous membrane and deeper tissues due to increased
bilirubin level of blood.
• Jaune in French means yellow.
• Normal Serum bilirubin level 0.5 to 1.5 mg/dl
• When bilirubin levels exceeds 2 mg/dl , it is termed Jaundice.

19. TYPES OF JAUNDICE
1. PREHEPATIC / HEMOLYTIC JAUNDICE
2. HEPATIC/ HEPATOCELLULAR JAUNDICE
3. POSTHEPATIC / OBSTRUCTIIVE JAUNDICE.