This document summarizes the normal constituents of blood, including their structure and functions. It discusses hematology and hematopoiesis, the process of blood cell production in the bone marrow and lymphoid tissues. The major cell types produced - red blood cells, white blood cells (neutrophils, lymphocytes, etc.), and platelets - are each described in terms of their development, structure, and role in the body. Regulation of hematopoiesis and the different cell lineages (myeloid vs. lymphoid) is also overviewed.
Normal Constituents of Blood - Pathology - MLT, ATOT, RDT
1. Normal Constituents of Blood,
Their Structure and Functions
Dr. Salman Ansari(MBBS)
Tutor, Dept. of Pathology
Kanachur Institute of Medical Sciences
4. Hematopoiesis/hemopoiesis
“Process of production of blood cells”
Hematopoietic system:
- Consists of all the organs and tissues involved in
hematopoiesis - Myeloid tissue and Lymphoid tissue
Hematopoietic stem cell(HSC): Progenitor of all the cells in blood -
gives rise to both myeloid and lymphoid series
5.
6. Myeloid tissue
Consists of:
- Bone marrow
- Cells derived from it, like:
RBC(erythrocytes)
WBCs(leukocytes): which consist of
granulocytes(neutrophils, eosinophils and basophils),
monocytes and agranulocytes(lymphocytes)
Platelets(thrombocytes)
8. Sites of hematopoiesis
● In fetus: yolk sac, liver, spleen, bone marrow
● In infants: bone marrow
● In Adults: bone marrow
9.
10.
11. Regulation of hematopoiesis
Hematopoiesis is regulated by a number of hematopoietic growth
factors or cytokines, such as
● Stem cells: Stem Cell Factor, Interleukin-6(IL-6) and FLT3-
ligand
● Common Myeloid Progenitor(CMP) cell: Granulocyte-
Macrophage Colony Stimulating Factor(GM-CSF), Granulocyte
CSF(G-CSF), erythropoietin, thrombopoietin
● IL-3, 5, 6 and 11
14. Myeloid series Lymphoid series
RBCs(erythrocytes) B-cells
WBCs(neutrophils,
eosinophils, basophils,
monocytes)
T-cells
Platelets(thrombocytes) NK cells
15. RBC/erythrocytes
Production of RBCs is called Erythropoiesis.
Stages of erythropoiesis:
Proerythroblast → Early Erythroblast → Intermediate
Erythroblast(normoblast) → Late erythroblast → Reticulocyte
→ Mature RBC
20. WBCs/leukocytes
Process of formation of WBCs - “leukopoiesis”
- Myeloid series - Myeloid stem cell develops into
granulocytes(neutrophils, eosinophils, basophils) -
“myelopoiesis”
- Lymphoid series - Lymphoid stem cell develops into
agranulocytes(lymphocytes) - “lymphopoiesis”
21.
22.
23.
24. Neutrophil/polymorph
- 40-80% of WBCs
Structure:
- Diameter: 13 µm
- Multi-lobed nucleus
- Fine pink granules
Functions:
- 1st line of defense
- Acute inflammation
27. Monocytes
2 to 10%
Structure:
- Size: 15 to 18µm
- Nucleus: large, kidney-shaped
- Cytoplasm: Blue
Function:
Phagocytosis - transform into macrophages
28. Lymphocytes
20-40%
2 types: Small lymphocyte (6 to 10µm)
Large lymphocyte (12-15µm)
Structure:
- Nucleus: single, no lobes
- Cytoplasm: Pale blue
Function:
produce antibodies and cell-mediated immunity