cell biology

• What are the major cellular components of blood?

  Red blood cells, white blood cells, and platelets
• What is the primary focus of the lectures on blood?

  Understanding the cellular regulation of blood components
• What role does Erythropoietin play in red blood cell production?

  It stimulates the production and differentiation of red blood cells
• What environmental condition does Erythropoietin sense?

  Blood oxygen levels
• What are the components of platelet surface molecules?

  Proteins and glycoproteins involved in clotting
• How does blood flow impact platelets?

  It affects their activation and aggregation
• What is the basis of H antigen modification in blood types?

  It determines the ABO classification of blood types
• Why is the Rhesus factor important in pregnancy?

  It can lead to Rh incompatibility between mother and fetus
• What is the primary function of red blood cells?

  Transporting oxygen from lungs to tissues
• Where are red blood cells produced?

  In the bone marrow
• What pigment do red blood cells contain for oxygen transport?

  Hemoglobin
• What happens to hemoglobin in the lungs?

  It combines with oxygen to form oxyhemoglobin
• What is the lifespan of red blood cells?

  About 4 months
• What shape do red blood cells have and why?

  Biconcave disc shape to increase surface area for diffusion
• Where are old red blood cells broken down?

  In the liver, spleen, and bone marrow
• What is the role of hematopoietic stem cells?

  They are the source of all blood cell types
• How are precursor cells separated in hematopoiesis?

  Based on surface protein signatures
• What triggers erythrocyte production?

  Erythropoietin (Epo) cytokine
• What happens to CFU-E cells in the absence of Epo?

  They undergo apoptosis
• How does Epo binding affect CFU-E cells?

  It prevents apoptosis and triggers gene transcription for RBC maturation
• What regulates Epo synthesis?

  Oxygen levels in the blood
• What happens to HIF-1α under low oxygen conditions?

  It is stabilized and activates Epo gene transcription
• What is the structure of Epo similar to?

  Growth hormone, prolactin, G-CSF, and thrombopoietin
• What is the size of a megakaryocyte?

  Approximately 50-100 µm in diameter
• What is the function of megakaryocytes?

  Production of platelets
• What is the diameter of platelets?

  1. 3 µm
• What are the four stages of platelet activation?

  Adhesion, aggregation, secretion, and procoagulant activity
• What is the role of integrin in platelets?

  It is involved in platelet activation and binding
• What happens to integrin during clot formation?

  It binds to other cytoskeletal elements
• What is von Willebrand factor's role in platelet activation?

  It is crucial for platelet adhesion during clot formation
• What are some activation factors for platelets?

  ADP and collagen
• What is the significance of reticulocytes in blood disorders?

  They are important markers for diagnosing blood disorders
• What percentage of erythrocytes do reticulocytes represent in adult blood?

  0.6% to 2.9%
• What is the role of reticulocytes in understanding erythropoiesis?

  They are fundamental to understanding the process of red blood cell production
• What is the significance of the hematopoietic stem-cell niche?

  It supports the maintenance and function of hematopoietic stem cells
• What types of cells are found in the bone marrow niche?

  Osteoblasts, osteoclasts, hematopoietic cells, and fibroblasts
• What is the role of SCF in the hematopoietic stem-cell niche?

  It is a hormone that supports stem cell maintenance
• What is the conclusion of the immunofluorescence experiment on HSCs?

  HSCs localize close to SCF-expressing cells
• What is the significance of hemoglobin's cooperative binding?

  It allows efficient unloading of oxygen in tissues
• What does P50 represent in hemoglobin function?

  The pO2 at which half the oxygen-binding sites are occupied