Body fluids and circulations

• Body fluids


  Fluids that aid in regulation of organisms, most commonly used by higher organisms including humans for transport of substances
• Components of blood


  • Matrix (55%)
  • Formed Elements (45%)

  
• Formed Elements


  • Red blood cells (erythrocytes)
  • Platelets (thrombocytes)
  • Leukocytes (white blood cells)

  
• Red blood cells

  • Formed in red bone marrow
  • Formed from granulate granulocyte megakaryocyte
  • Anucleate
  • Biconcave shape
  • Contain haemoglobin (12-16g/100ml blood)
  • Lifespan of 120 days
  • Destroyed in spleen
• Platelets


  • Fragments of cells
  • Anucleate
  • Help in blood clotting
  • Lifespan shorter than red blood cells
• Neutrophils


  • Phagocytic
  • Polymorphonuclear
  • Nucleus changes shape
• Eosinophils


  • Stained by basic dyes
  • Involved in allergic reactions
• Basophils


  • Stained by both basic and acidic dyes
  • Secrete histamine
• Monocytes


  • Phagocytic
  • Differentiate into macrophages
• Lymphocytes


  • Synthesized and activated in red bone marrow and thymus
  • Involved in cell-mediated and humoral immunity
• Blood clotting


  1. Injured tissue releases thromboplastin

  2. Prothrombin converted to thrombin

  3. Fibrinogen converted to fibrin threads

  4. Forming a mesh to block RBCs
• Blood groups


  Antigens on surface of RBCs, antibodies in plasma

  
• Blood group antigens


  • A
  • B
  • Rh
• Erythroblastosis foetalis is due to Rh incompatibility between mother and fetus
• Erythroblastosis foetalis


  1. Rh+ fetus

  2. Rh- mother

  3. Antibodies in maternal blood recognize fetus as foreign, killing its RBCs

  4. Causing anaemia and jaundice in fetus
• Solution to erythroblastosis foetalis is injecting anti-Rh antibodies after birth of Rh+ baby
• Parts of the heart


  • Pericardial cavity
  • Atria
  • Ventricles
  • Valves
  • Blood vessels
• Left ventricle


  • Has thickest wall
• Arteries vs Veins


  Arteries have thicker tunica media, smaller lumen, no valves

  Veins have thinner tunica media, larger lumen, have valves

  
• Abnormal blood cell counts


  • Erythrocytopenia/Polycythemia
  • Leukocytopenia/Leukocytosis
  • Thrombocytopenia

  
• Leukemia is blood cancer with extremely high white blood cell count
• Types of circulatory systems


  • Open
  • Single
  • Incomplete double
  • Complete double
• Cardiac cycle


  Alternating contraction (systole) and relaxation (diastole) of heart
• Cardiac cycle


  1. AV valves close

  2. Semilunar valves open

  3. Ventricles contract

  4. AV valves open

  5. Semilunar valves close

  6. Ventricles relax
• Electrocardiogram


  • P wave marks atrial depolarization

  QRS complex marks ventricular depolarization

  T wave marks ventricular repolarization
• Heart rate


  Tachycardia (>100bpm)

  Bradycardia (<60bpm)
• Damage to SA node does not immediately stop beating of heart
• Hypertension is blood pressure >130/80 mmHg, hypotension is <90/60 mmHg
• Arrhythmia is abnormal heart rhythm
• Platelets


  Fragments of cells without a nucleus that play a crucial role in blood clotting. Lifespan is shorter than red blood cells.
• Leukocytes


  Type of white blood cell with a nucleus that are involved in the immune response. Can be divided into several types, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils.