BMS 201 Leukocytes and Leukopoiesis PDF Fall 2024

BMS 201 Leukocytes and Leukopoiesis Prof. Dr. Manal Shaaban Hafez Professor of Histology and cell biology Faculty of Medicine, Fall 2024 Galala University gu.edu.eg 1. Classify leucocytes. 2. Classify granulocytes. 3. Descri...

BMS 201 Leukocytes and Leukopoiesis Prof. Dr. Manal Shaaban Hafez Professor of Histology and cell biology Faculty of Medicine, Fall 2024 Galala University gu.edu.eg 1. Classify leucocytes. 2. Classify granulocytes. 3. Describe & compare LM and TEM structure of each type of blood granular leucocytes 4. Define and classify leucopoiesis. 5. List the steps of granulopoiesis. 6. Describe the histological structure of each cell during granulopoiesis 7. Describe the histological structure of each type of agranulocytes. 8. Compare between the histological structure of small and medium-sized lymphocytes. 9. Compare between the histological structure of lymphocytes and monocytes. 10. Correlate the clinical importance of monocytes to inflammatory process. 11. Describe the steps of development of B and T lymphocytes  Leukocytes (white blood cells or WBCs) are motile cells. They leave the blood stream and migrate to the tissues and perform their activities related to body immunity. Most granulocytes undergo apoptosis in the connective tissue. Number about 6000 – 10,000/mm³ They are true cells. They have lobulated nuclei (except lymphocytes have large spherical nucleus}, few mitochondria, few Golgi, poorly developed RER and glycogen granules (anaerobic glycolysis). Have short life span (most last hours to days). ✓ Leucocytosis:- An increase in the total number above 11,000/mm³. ✓ Leucopenia:- A decrease in the total number below 4000/mm³.  Leucocytes(WBCs) (6000 – 10,000/mm³( Granular Non-granular - Neutrophils -Lymphocytes - Eosinophils - Monocytes - Basophils  Neutrophils: (Polymorphs) (Polymorph-nuclear leucocytes) They constitute 60%-70% of circulating leukocytes (The highest leukocytic number). They kill and phagocytose bacteria. Neutrophils are 12-15 μm in diameter. Band neutrophils (immature) are not more than 3-5% in blood film under normal condition. Life span: 6-8 hours in blood and 1-4 days in connective tissue. Band neutrophil  They are inactive cells in circulating blood and become activated on connective tissue. The nucleus having two to five lobes linked by thin chromatin strand. The cytoplasm: show 2 types of granules:- ✓ 1.Neutrophilic (specific) granules: are smaller, 80% of granules & stain faintly pink. ✓ They contains (extracellular matrix ) ECM-degrading enzymes such as collagenases to breakdown matrix components and Pus formation ✓ They are also containing alkaline phosphatase, and lactoferrin (bacteriostatic).  Neutrophiles ✓ 2.Azurophilic granules: are large dense lysosomes & 20% of granules ▪ Their role is killing and degrading the engulfed microorganisms. ▪ They are lysosomes which contain hydrolytic enzymes, proteolytic and lipolytic enzymes (bacteriotoxic). ▪ They also release many cytokines and chemokines that attract other leukocytes to the site of inflammation. ▪ Apoptotic neutrophils, bacteria, semi-digested material, and tissue-fluid form a viscous, usually yellow colored fluid called pus. Neutrophilia (>75%) means increase number in acute inflammatory conditions and pyogenic infections. Intense muscular activity. Neutropenia (