Blood

• What are the main functions of blood?

  Transportation, regulation, restriction, defense, stabilization
• How does blood regulate the pH of interstitial fluids?

  By maintaining electrolyte composition
• How much blood is typically in the human body?

  About 5 litres
• What makes up about 60% of blood?

  Plasma, including water and organic molecules
• What are the components of plasma?

  Water, ions, organic molecules, gases
• What percentage of blood is made up of cellular elements?

  About 40%
• What are the three main components of blood?

  Plasma, red blood cells, white blood cells
• Why are red blood cells considered not actual cells?

  They have no nucleus
• What is the role of hemoglobin in red blood cells?

  Transports oxygen and carbon dioxide
• What gives blood its red color?

  Hemoglobin containing iron
• What is the structure of hemoglobin?

  Consists of 4 polypeptides: 2 alpha, 2 beta
• What is the significance of gamma chains in fetal hemoglobin?

  Higher affinity for oxygen than adult hemoglobin
• How many heme groups can bind oxygen?

  Four heme groups
• What is the role of neutrophils in the immune system?

  Fight bacterial infections by engulfing bacteria
• What are the types of lymphocytes?

  B cells, T cells, NK cells
• What do monocytes develop into?

  Macrophages and dendritic cells
• What is the function of eosinophils?

  Combat parasitic infections and allergic responses
• What is the role of basophils?

  Involved in allergic reactions
• What is hematopoiesis?

  Blood cell formation
• What type of stem cell is involved in hematopoiesis?

  Pluripotent hematopoietic stem cell
• What happens to erythroblasts during red blood cell production?

  They become smaller and visible hemoglobin appears
• What is the function of megakaryocytes?

  Produce platelets
• What is the stroma in bone marrow?

  Supporting tissue for blood cell development
• What happens to reticulocytes in the bone marrow?

  They expel their nucleus to become erythrocytes
• What are the two colors of bone marrow?

  Yellow and red
• What is the role of the venous sinus?

  Drains deoxygenated blood and CSF
• What is erythropoiesis?

  Production of red blood cells
• What triggers the release of erythropoietin?

  Low oxygen levels in the blood
• How many red blood cells does the bone marrow produce per second?

  About 3 million
• Why do athletes train at high altitudes?

  To increase erythropoietin and red blood cells
• What is hematocrit?

  Volume percentage of red blood cells in blood
• How is hematocrit measured?

  By centrifuging a blood sample
• What happens to hematocrit levels above 50%?

  Disqualification in sports
• What are symptoms of anemia?

  Breathing problems and lethargy
• What causes hemolytic anemias?

  Cells rupture at an abnormally high rate
• What is polycythemia?

  High red blood cell count
• What is aplastic anemia?

  Caused by certain drugs or radiation
• What is the role of iron in blood?

  Required for heme production
• What is the function of folic acid in blood production?

  Required for DNA synthesis
• What is the role of vitamin B12?

  Required for DNA synthesis