COMPRE (PASSED!! 🫶🏻)

• HEMATOPOIESIS

  • It is a continuous and regulated process of blood cell development/division wherein there is cell renewal, proliferation, differentiation and maturation
• Each of our blood cell has their own lifespan

  • RBC: 120 days
  • WBCs: has variety of lifespan depending on their type
• In hematopoiesis, once this blood cell dies, what will happen?

  • renewal
  • proliferation
  • differentiation
  • maturation
• PHASES OF HEMATOPOIESES

  1. mesoblastic phase
  2. hepatic phase
  3. myeloid or medullary phase
• Mesoblastic phase

  • Earliest stage of hematopoiesis
  • 19-20 days to 8-12 weeks of gestation
  • As early as 19-20 days of conception, there is already hematopoiesis going on
  • it happens in the mesodermal cells of the yolk sac
  • development primarily of erythroblast
  • Aside from the erythroblasts, other cells produced in this phase include:
  • Granulocytes, Monocytes
• Primary erythroblasts (sa mesoblastic phase)

  • cells that provide O2 to the developing fetus
  • they contain embryonic hemoglobin wc are the
  • gower 1
  • gower 2
  • portland
• Hepatic phase

  • 5th or 7th week to 6 months of gestation
  • Liver is the major site of blood cell development
  • Cells are morphologically identifiable
  • Recall: Bone marrow is the main site of blood cell production. However, earlier in the life of a person, blood cell production starts in different organs of the body. In the hepatic phase, there is extramedullary hematopoiesis
  • Production of megakaryocytes that gives rise to platelets
  • Hemoglobin types:
  • HbF/Fetal hgb- predominant
  • HbA/Adult hgb- only present in detectable amounts
• Myeloid/Medullary phase

  • Phase of hematopoiesis wherein blood cell happens in the bone marrow (medulla or inner part of the bone marrow) already
  • Last stage of hematopoiesis
  • This phase last from 5th month of gestation until lifetime
  • After hepatic phase, we will proceed to myeloid or medullary phase wherein this phase would last throughout a person’s lifetime wherein blood cells are being produced inside the medulla of your bone marrow.
  • EPO, G-CSF, GM-GSF, HbF, HbA, HbA2
• Homeostasis

  • is the body's tendency to move toward physiological stability. In vitro testing of blood and other body fluids must replicate exact environmental body conditions. These conditions should include the following:

  1. osmotic concentration
  2. ph
  3. temperature
• Osmotic concentration in in vitro testing of blood is the body/cellular water concentration, composed of 0.85% sodium chloride, which is termed isotonic.
• In a hypotonic solution, where there is a greater amount of H2O in relationship to a lesser amount of solutes, water enters the cell, causing the cell to swell and may lyse.
• In a hypertonic solution, where there is a lesser amount of H2O in relationship to a greater amount of solutes, water leaves the cell, causing the cell to may crenate.
• The pH reference range for venous blood is 7.36-7.41, and for arterial blood it is 7.38-7.44.
• Normal body temperature is 37.0°C.
• Blood specimens should be analyzed as soon as possible to prevent cellular breakdown.
• Conditions for in vitro blood testing

  1. Osmotic concentration is the body/cellular water concentration, composed of 0.85% sodium chloride. This normal osmotic concentration is termed isotonic. In a hypotonic solution (greater amount of H2O in relationship to lesser amount of solutes), water enters the cell; the cell swells and may lyse. In a hypertonic solution (lesser amount of H2O in relationship to greater amount of solutes), water leaves the cell; the cell may crenate.
• Conditions for in vitro blood testing (cont)

  2. pH reference range: Venous blood range 7.36-7.41; arterial blood range 7.38-7.44

  3. Temperature: Normal body temperature is 37.0°C. Blood specimens should be analyzed as soon as possible to prevent cellular breakdown
• ADULT HEMATOPOIETIC TISSUES

  1. Bone marrow- main site of hematopoiesis in adults
  2. liver- usually function for coagulation factor synthesis
  3. coagulation factors- essential proteins found in the plasma that aids in blood coagulation
  4. spleen- filter of circulating blood
  5. thymus- t cell differentiation
• Principles of cell maturation:

  1. changes in cytoplasm
  2. changes in nucleus
  3. changes in cell size
• Cell maturation: Changes in cytoplasm

  • immature cell stains deep blue color (basophilic), as it matures, lessening of the deep blue color is observed
  • the staining is the first change in cytoplasm
  • granules appear in the cytoplasm as the cell matures (specific granules- granulocyte)
  • amount of cytoplasm increases as the cell matures
• Cell maturation: Changes in the nucleus

  • Size of the nucleus decreases as the cell matures
  • As the cell matures, nuclear chromatin pattern changes from fine and delicate to coarse and clumped form
  • Nuclear chromatin staining characteristics from reddish purple to bluish purple as the cell matures
  • Nucleoli is present in the early stages but disappears as the cell matures
• Stem cell theory

  • Monophyletic theory
  • from one common stem cell
  • all blood cells come from only one stem cell
  • Polyphyletic theory
  • each blood cell has its own unique stem cell
• Monophyletic theory

  • Wherein all blood cells being produced comes from one stem cell, the hemocytoblast
  • hemocytoblast, upon maturation, would differentiate into myeloid progenitor cell and lymphoid progenitor cell
• Stages of erythropoiesis

  1. Pronormoblast or Rubriblast
  2. Basophilic Normoblast or Prorubricyte
  3. Polychromatophilic Normoblast or Rubricyte
  4. Orthochromatic Normoblast or Metarubricyte
  5. Reticulocyte
  6. Erythrocyte or Mature Red Blood Cell
• Erythropoiesis is the process of producing red blood cells.
• Basophilic Normoblast or Prorubricyte is Deeply Basic.
• In Polychromatophilic Normoblast or Rubricyte, “Poly” means many.
• Aside from the deeply blue color, Polychromatophilic Normoblast or Rubricyte starts having a reddish or orange-red color due to the Hemoglobin production.
• Polychromatophilic Normoblast or Rubricyte is the start of Hemoglobin Production.
• Polychromatophilic Normoblast or Rubricyte is the last stage that is capable of undergoing Mitosis.
• In Orthochromatic Normoblast or Metarubricyte, “Ortho” means true.
• At this stage of Red Blood Cell Development, the true color of Erythrocyte or RBC will start to appear.
• Reticulocyte can be seen in the circulation, but only in minute amount.
• Shift Reticulocytes are a measure of Bone Marrow Activity.
• Erythrocyte have biconcave disc shape, and carries Oxygen.
• The life span of Erythrocyte is 120 days.
• One pronormoblast will give rise to 8 RBCs
• Anemia

  • Decrease in Oxygen-carrying capacity of the blood. When we say a decrease in oxygen carrying capacity of the blood, anong cell ang may problem? It is our RED CELL.
  • Is physiologically defined as a condition in which the circulating blood lacks the ability to oxygenate body tissues. There is less blood cells in anemia, to be exact, LESS RED BLOOD CELLS. Kaya nag kakaproblem tayo sa oxygen carrying capacity because of the diminished number of the red cells.
• Mechanisms of Anemia

  1. Ineffective erythropoiesis

  • From the name itself, INEFFECTIVE. Meaning THERE IS ERYTHROPOIESIS BUT THE BLOOD CELLS BEING PRODUCED ARE INEFFECTIVE/FAULTY they cannot function well. There is problem in the blood cells being produced. * May blood cell pero faulty.

  2. Insufficient erythropoiesis

  • From the name itself, INSUFFICIENT. Meaning THERE IS ERYTHROPOIESIS BUT THE NUMBER OF BLOOD CELLS BEING PRODUCED IS FEW. The blood cells being produced are normally functioning but it is few. * May blood cell pero konti lng sila.
• Granulopoiesis (WBC)

  1. Myeloblast
  2. promyelocyte
  3. myelocyte
  4. metamyelocyte
  5. band cell
  6. segmenters