L4: Cardiovascular system (blood)

• What is blood primarily composed of?

  A liquid that transports materials
• What percentage of blood volume is plasma?

  55%
• What percentage of total blood is made up of red blood cells?

  45%
• What percentage of total blood do white blood cells and platelets constitute?

  Less than 1%
• What are the main functions of blood?

  • Respiration: oxygen supply and carbon dioxide removal
  • Transport: nutrients, waste, and hormones
  • Protection: immune system function
  • Repair: tissue damage
  • Thermoregulation: heat loss management
• Where does haematopoiesis occur?

  In the bone marrow
• What type of bone marrow produces most blood cells?

  Red marrow in flat bones
• What is the role of yellow marrow?

  Produces some white blood cells
• What does bone marrow consist of?

  Blood cells at various development stages and stroma
• What are the components of stroma in bone marrow?

  Fibroblasts, macrophages, adipocytes, osteoblasts, osteoclasts, epithelial cells
• What are the branches of haematopoiesis?

  • Megakaryopoiesis/thrombopoiesis: production of platelets
  • Erythropoiesis: production of red blood cells
  • Granulopoiesis: production of granulocytes
  • Monocytopoiesis: production of monocytes
  • Lymphopoiesis: production of lymphocytes
• What produces haemopoietic growth factors in bone marrow?

  Stroma cells
• What are the components of plasma?

  • Water: solvent for substances
  • Sodium: osmotic balance
  • Potassium, calcium, magnesium, chloride, bicarbonate: pH buffering
  • Albumin: osmotic balance and pH buffering
  • Fibrinogen: clotting
  • Immunoglobulins: defense
  • Nutrients: glucose, fatty acids, vitamins
  • Waste products of metabolism
  • Respiratory gases: oxygen and carbon dioxide
  • Hormones
• What does totipotent stem cells mean?

  Can become any cells in the body
• What does pluripotent stem cells mean?

  Can become nearly all cells in the body
• What does multipotent stem cells mean?

  Can become several cells in the same family
• What does oligopotent stem cells mean?

  Can differentiate into few different cell types
• What is the common myeloid precursor?

  Can become any myeloid cells
• What is the common lymphoid precursor?

  Can become any lymphoid cells
• What are myeloblasts?

  Immature precursor cells for myeloid cells
• What are lymphoblasts?

  Immature precursor cells for lymphoid cells
• What is the role of natural killer cells?

  Kill foreign or cancerous cells
• Where is the spleen located?

  Upper left abdominal cavity
• What is the function of the spleen?

  Removes old or damaged blood cells
• How far apart are splenic cords from venous sinuses?

  3,000 micrometres
• How are cells filtered from blood in the spleen?

  Cells that cannot deform are filtered
• What happens to proteins in red blood cells during destruction?

  Broken down to amino acids for synthesis
• What is the porphyrin ring converted to?

  Bilirubin for liver processing
• What is the shape of red blood cells?

  Biconcave disks
• What is the diameter of red blood cells?

  7-12 micrometres
• Why do red blood cells lack a nucleus?

  To maximize space for oxygen
• Why do red blood cells lack mitochondria?

  To prevent using oxygen for energy
• What is the average lifespan of red blood cells?

  120 days
• What are the functions of red blood cells?

  • Transport oxygen
  • Transport carbon dioxide
  • Critical role in respiration
• What gives blood its red appearance?

  Haemoglobin (Hb)
• How many molecules of haemoglobin are in red blood cells?

  250 million molecules
• How many polypeptide chains does haemoglobin have?

  4 polypeptide chains
• What does each iron atom in haemoglobin bind to?

  One molecule of oxygen
• What is the Bohr effect?

  Factors that ease oxygen off-loading
• What are the components of cell membranes related to blood cells?

  • Glycolipids: ABO antigens
  • Proteins: Rhesus factor
  • Glycoproteins: various roles
  • Antigens: important for immune recognition