Recombination DNA Technology (Nucleic Acid Hybridization )
Primary lymphoid organ.pptx
1. Primary lymphoid organ
Bone marrow
Presented To:
Dr.S.Saranya
Asst. Prof of Microbiology
Sacred Heart College
Tirupattur.
Presented By:
R.Jayapriya (BP211513),
I M.Sc Applied Microbiology,
Sacred Heart College,
Tirupattur.
2. Bone marrow
Bone marrow is a spongy substance found in the center of the
bones. It manufactures bone marrow stem cells and other
substances, which in turn produce blood cells.
Each type of blood cell made by the bone marrow has an
important job.
Red blood cells carry oxygen to tissues in the body.
Platelets stop bleeding by helping blood clot.
White blood cells fight infections
3. 1. Bonemarrow is soft, flexible connective tissue present within the
bone cavities.
2. In humans and mice, bone marrow is the site of B cell origin and
development.
3. Arising from lymphoid progenitors, immature B cells proliferate
and differentiate within the bone marrow, and stromal cells within
the bone marrow interact directly with the B cells and secrete
various cytokines that are required for development.
4. Like thymic selection during T cell maturation, a selection
process within the bone marrow eliminates B cells with self-
reactive antibody receptors.
4. 5. Bone marrow is not the site of B-cell development in all species.
In birds, a lymphoid organ called the bursa of Fabricius, a lymphoid
tissue associated with the gut, is the primary site of B-cell
maturation.
6. In mammals such as primates and rodents, there is no bursa and
no single counterpart to it as a primary lymphoid organ. In cattle and
sheep, the primary lymphoid tissue hosting the maturation,
proliferation, and diversification of B cells early in gestation is the
fetal spleen.
7. Later in gestation, this function is assumed by a patch of tissue
embedded in the wall of the intestine called the ileal Peyer’s
patch,which contains a large number (1010) B cells. The rabbit, too,
uses gut-associated tissues such as the appendix as primary
lymphoid tissue for important steps in the proliferation and
diversification of B cells.
5.
6. RED BONE MARROW YELLOW BONE MARROW
Also known as Myeloid tissue. Also known as Fatty tissue.
Hematopoietic (formation of blood cell
components) in nature and produces RBC,
WBC & Platelets.
Multipotent Stromal (connective tissue cell of
any organ) in nature and produces Fat,
Cartilage and Bone.
Gets its red color from the hemoglobin in
the erythroid cells.
Gets its yellow color from the carotenoids in
the fat droplets in the high number of fat
cells.
High Vascular supply. Poor Vascular supply.
Function - Helps to remove old cells from
circulation.
Function - When blood supply is extremely
low, yellow marrow can be converted to red
marrow in order to produce more blood cells.
DifferencebetweenRedBoneMarrowandYellowBoneMarrow
7. Functionsof Bone Marrow
Bone marrow is the site of B - cell origin and development.
A bone marrow transplant can save the lives of people battling
leukemia, lymphoma, and other blood cancers.
Bone marrow generates RBCs which carry oxygen to the tissues.
Bone marrow generates Platelets or Thrombocytes help prevent
bleeding and aid in clotting of blood.
Granulocytes (Neutrophils, Basophils & Eosinophils) and Macrophages
fight against microbial infections. They also remove dead cells and
remodel tissue and bones.
