Haemopoiesis and Erythropoiesis Quiz

Haemopoiesis

• Haemopoiesis is the production of blood cells.
• It's a tightly regulated process.
• It involves several stages of development for different blood cell types.

Aims and Objectives

• This lecture outlines haemopoiesis processes.
• Students will be able to explain the importance of effective haemopoiesis.
• Students will be able to describe the major components of bone marrow.
• Students will be able to describe the mechanism of haemopoiesis and the importance of growth factors.
• Students will be able to explain the value of bone marrow analysis.

Types of Haemopoiesis

• Erythropoiesis: Red blood cell production.
  • Erythrocytes transport oxygen from lungs to tissues.
  • Regulated by growth factors, cytokines, and environmental factors, and apoptosis.
• Leucopoiesis: White blood cell production.
  • Leucocytes defend the body against infection.
• Thrombopoiesis: Platelet production.
  • Thrombocytes prevent blood loss at injury sites.

Ontogeny of Haemopoiesis

• Adults: Bone marrow in vertebrae, ribs, sternum, skull, sacrum, and hip bones.
• Infants: Bone marrow in practically all bones.
• Foetus:
  • 0-2 months: Yolk sac of embryo
  • 2-7 months: Liver and spleen
  • 5-9 months: Bone marrow (sole site at birth)

Haemopoietic Stem & Progenitor Cells

• Pluripotent stem cell is the origin of all blood cells.
• CFU (colony-forming unit) cells are progenitor cells.
  • Different CFU's for different cell types (erythroid, myeloid, lymphoid).
• The different progenitor cells produce different types of blood cells.
• Diagram showing the differentiation of haemopoietic cells from pluripotent stem cells.
  • Cells differentiate via various lineages.
  • CFU/E = erythroid progenitor in red blood cell production
• Erythroid progenitor CFU-E, forms the red blood cell line.
• CFU-GM = granulocyte-macrophage progenitor.
• CFU-Meg = megakaryocyte progenitor forms platelets.
• CFU-L = lymphocyte progenitor.

A Glance at Bone Marrow Stroma

• Stroma consists of fibroblasts, endothelial cells, and macrophages.
• Factors mediate cell-to-cell interaction.
• Diagram illustrates the roles of various components of the bone marrow.
  • Growth factors and receptors are central to the regulation process.

Examples of Growth Factors

• Interleukins (ILs): Stimulate the production of growth factors and other mediators. Ex. IL-1, IL-3, IL-4, IL-6.
• Colony-stimulating factors (CSFs): Stimulate proliferation and differentiation of specific cell types, such as granulocyte-macrophage CSF (GM-CSF).
• Erythropoietin (EPO): Regulates red blood cell production in the kidneys.
• Thrombopoietin: Stimulates the maturation of megakaryocytes and platelet production in the liver.

Apoptosis

• Apoptosis is programmed cell death.
• It's a tightly regulated process crucial for removing damaged or unwanted cells.
  • Morphological features of an apoptotic cell
• Key molecules and factors involved in apoptosis regulation.

Specific Haemopoiesis

• Specific processes for formation.

Erythropoiesis - Formation of RBC

• Erythropoiesis forms red blood cells.
• Diagram shows the steps and stages of erythropoiesis, progressing from blast to reticulocyte.

Erythropoiesis Regulation by EPO

• Erythropoiesis is driven by erythropoietin (EPO).
• Low oxygen levels stimulate EPO release to increase red blood cell production.
  • Peritubular cells in the kidneys detect oxygen levels.
• EPO regulated by oxygen sensing pathway.

EPO Levels

• EPO levels correlate with haemoglobin concentration.
• Lower haemoglobin levels associate with higher EPO levels.

Thrombopoiesis - Platelet Production

• Thrombopoiesis involves platelet production.
• Diagram illustrates stages for megakaryocyte precursor cells.
  • Describes the process that results in mature platelets.

Granulopoiesis

• Granulopoiesis forms granulocytes (neutrophils, eosinophils, basophils).
  • Stages of development from stem cells to mature cells.
  • Proliferation and differentiation factors.
• Production regulated by M-CSF, IL-3, and GM-CSF, controlling proliferation/differentiation

Mature Granulocytes

• Images of mature neutrophils, eosinophils, basophils and monocytes.
  • Diagrams demonstrating morphological characteristics to aid identification.

Lymphocyte Production

• B and T cells arise from haemopoietic stem cells (IL-7).

B-Cell

• B-cell receptor, activation and differentiation aspects.
  • Activation leads to immunoglobulin secretion.

T-Cell

• T cells develop from cells migrating to the thymus.
• Helper T cells (CD4) and Cytotoxic T cells (CD8) are two types.

Marrow Analysis

• Determining the status of blood cell production
• Measuring blood cell production for diagnostic purposes.

Obtaining Bone Marrow

• Procedures to extract samples.
  • Location of sample sites (hip bone, breastbone).
• Preparation process (cleaning bone with iodine/alcohol solutions).
• Placement of extraction needle for bone marrow aspiration.

Marrow Aspiration

• Examination techniques for obtained marrow
  • Staining of slides to visualize components of the bone marrow.

Bone Marrow

• Appearance, composition, and cell distribution (fat cells, proteins, and blood cells).
• Ratio of myeloid to erythroid progenitor cell types.
  • Ratio is clinically relevant to disease or pathology.

M/E Ratio

• Analyzing the ratio of myeloid to erythroid cells.
  • Variations in ratio indicate different blood disorders/diseases.

Fluorescence Flow Cytometry

• Uses of flow cytometry to confirm malignancies or monitor minimal residual disease.
  • Identification of white blood cells (WBC's) by different markers.
  • Measures CD34+ cells helpful in measuring bone marrow precursors.

Core Textbook/Additional Reading

• Comprehensive haemopoiesis-related material from relevant books and chapters.

Test your knowledge on the processes of haemopoiesis and erythropoiesis with this engaging quiz. Explore the functions, sites, and factors affecting blood cell production. Perfect for students and enthusiasts of biology and medical sciences.