Hematopoiesis

• Hematopoietic stem cells (HSC) are undifferentiated cells that can differentiate into all types of blood cells.
• The cytoplasm of an immature cell is usually blue or basophilic due to RNA content.
• If the cell is young, the color is darker.
• The more mature the cell, the less basophilic because of the less RNA.
• If the cell is old, it’s pale.
• In myeloid cells, the cytoplasm contains granules which contain some enzymes that distinguish the myeloid stem cells from other cells.
• Red (acidic) Dye is acidophilic or eosinophilic granules.
• Blue (basic) Dye are called basophilic granules.
• Neutrophilic Granules are basic and acidic dye.
• Special feature of the maturation of erythrocyte: at first, immature cells contain no hemoglobin.
• Gradually the hemoglobin starts to appear as the cell becomes mature until most mature cell contains the standard and maximal amount of it.
• Mature stage: the nucleus is no longer necessary and is eliminated by nucleolysis or extinction.
• The heel stick procedure is a method of skin puncture.
• Venipuncture is the method of inserting a needle attached to a syringe to a palpable vein to collect blood for laboratory testing.
• Avoid skin puncture in inflamed and pallor areas, cold and cyanotic areas, congested and edematous areas, and scarred and heavily calloused areas.
• Venous blood is the most widely used blood sample in all laboratory tests.
• Avoid skin puncture on the base of the finger, earlobe, and middle portion of the plantar surface of the heel/toe.
• Finger puncture is a method of skin puncture using the third or fourth finger of the non-dominant hand.
• Capillary puncture is preferred in infants and very young children due to their small blood volume and risk of anemia, risk of cardiac arrest when large quantities of blood are removed, difficulty in venipuncture, and risk of injury due to restraint needed for venipuncture.
• Earlobe puncture is a method of skin puncture.
• Sites of skin puncture include the finger (middle or ring), earlobe, and lateral portion of the plantar surface of the heel/toe.
• Erythrocytes are anucleate when matured because they stop undergoing mitosis.
• Interleukins have interacting systems with amplification potential.
• Interleukin-1 (IL-1) is encoded by different genes on chromosomes 2.
• Hematopoietic growth factors (cytokines) include CSF, GM-CSF, M-CSF, G-CSF, and M-CSF.
• CSF is a cytokine that promotes the division and differentiation of hematopoietic cells.
• Interleukins exhibit multiple biologic activities such as autoimmune reactions, inflammatory reaction, and hematopoiesis.
• Interleukins have synergic interactions with other cytokines and growth factors.
• Interleukins (ILs) are a group of compounds that are synthesized by lymphocytes, macrophages, and matrix cells in the marrow and interact with cells to initiate, stimulate or influence the maturation of blood cells.
• Hematopoietic stem cells (HSCs) are blood marrow cells that are capable of producing all types of blood cells.
• Interleukins are effective at very low concentration.
• Stem cells are cells that have extensive proliferative capacity and the ability to give rise to new stem cells.
• As the cell matures, the shape of the nucleus changes too.
• Granulocytes in which the nucleus divides into segments or lobes as it grows older.
• Neutrophils have 3 - 5 lobes which is normal, if it’s getting old, its lobes multiply and becomes 10 or more.
• Hypersegmented neutrophils are one of the hallmarks of anemia.
• Hyposegmented: absence of lobes
• The megalocytes nucleus takes a longer time to mature than its cytoplasm.
• Cases of megablastic anemia has late maturation.
• In leukemia, two nuclei may be present; one may be diploid and the other may be polyploidy.