   The negative pressure allows the lungs to             It is conducted through blood vessels
    passively fill with air as they relax.                 (arteries and veins).
   The left and right lungs are slightly                 It is made up of red blood cells, white
    different in size and shape due to the heart           blood cells, platelets, and liquid plasma.
    pointing to the left side of the body.
   The left lung is therefore slightly smaller        Blood types of parents and their children
    than the right lung and is made up of 2               Parents’ Blood Types      Possible Children
    lobes while the right lung has 3 lobes.               A&A                       A, O
   The interior of the lungs is made up of               A&B                       A, B, AB, O
    spongy tissues containing many capillaries            A & AB                    A, B, AB
                                                          A&O                       A, O
    and around 30 million tiny sacs known as              B&B                       B, O
    alveoli.                                              B & AB                    A, B, AB
   The alveoli are cup-shaped structures                 B&O                       B, O
    found at the end of the terminal                      AB &AB                    A, B, AB
                                                          AB & O                    A, B
    bronchioles       and      surrounded       by
                                                          O&O                       O
    capillaries.
CIRCULATORY            SYSTEM        or   Cardio-      Red Blood Cells (RBCs) or Erythrocytes
vascular System
                                                          These are used to carry oxygen to all parts
   It is a network of organs and vessels that is          of the body and to bring carbon dioxide to
    responsible for the flow of blood,                     the lungs.
    nutrients, hormones, oxygen and other
                                                          RBCs have a lifetime of about 120 days.
    gases to and from cells.
                                                          The haemoglobin in the red blood cell is
   It contains the heart, blood and blood                 the carrier for oxygen and carbon dioxide.
    vessels.
                                                          One RBC contains about 280 haemoglobin
   It includes the pulmonary circulation, a               molecule.
    "loop" through the lungs where blood is
                                                          In the process of being formed they go
    oxygenated; and the systemic circulation,
                                                           through a unipotent stem cell stage. They
    a "loop" through the rest of the body to
                                                           have the job alongside the white blood
    provide oxygenated blood.
                                                           cells of protecting the healthy cells.
   The systemic circulation can also be seen
    to       function     in      two      parts–a     White Blood Cells (WBCs) or Leukocytes
    macrocirculation and a microcirculation.
   An average adult contains five to six                 These are responsible for fighting
    quarts (roughly 4.7 to 5.7 liters) of blood.           infection by identifying, engulfing, and
                                                           destroying foreign organisms.
Blood                                                     They are active in the immune response by
                                                           producing antibodies to foreign organisms.
   It is a constantly circulating fluid
                                                          Granulocytes or neutrophils, eosinophils,
    providing the body with nutrition, oxygen,
                                                           basophils, monocytes, and lymphocytes
    and waste removal.
                                                           are the 5 different types of WBCs.
   It is mostly liquid, with numerous cells
                                                          Neutrophils are the most abundant of all
    and proteins suspended in it, making blood
                                                           the WBCs.
    "thicker" than pure water.
   It transports nutrients, proteins needed for
    blood clotting, and waste products.
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