Platelets or Thrombocytes or Yellow Blood              Veins
                                                           These are the blood vessels that carry
   These are small cell fragments responsible              deoxygenated blood back to the heart.
    for the clotting of blood and the formation            It contains about 75% of blood.
    of scabs.                                              The walls of the veins are thinner than the
   They form in the red bone marrow from                   arteries.
    large megakaryocyte cells that periodically            Venules are known as the smallest of the
    rupture and release thousands of pieces of              veins.
    membrane that become the platelets.                    It has no pulse and blood travels smoothly.
   They do not contain a nucleus and only             Capillary
    survive in the body for up to a week
    before macrophages capture and digest                  These are the smallest blood vessels in the
    them.                                                   body.
                                                           It contains about 5% of blood at any time,
Plasma                                                      and no pulse can be felt in one.
                                                           These blood vessels are act as a link
   It is the non-cellular or liquid portion of
                                                            between arteries and veins.
    the blood that makes up about 55% of the
                                                           It has a single layer of endothelial cells.
    blood’s volume.
                                                            Water and other small molecule
   Approximately, 90% of blood plasma is
                                                            substances can pass through this wall.
    water and remaining 10% are proteins,
    inclusions and waste products etc.                 Atrium : Either of the two (left and right)
   The plasma functions as a transportation           upper chambers of the heart. Also called
    medium for these substances as they move           auricles
    throughout the body.                               Pulmonary : Used to describe blood vessels
                                                       that carry blood between the heart and the
Blood Vessels
These are the tubular structure carrying blood         Aorta : The largest artery which directs blood
through the tissues and organs                         to every organ but the lungs
There are three major types of blood vessels:          Lumen : The inner open space of a tubular
arteries, capillaries and veins.                       organ, in this case the blood vessels
Arteries                                               Vena Cava : Either of two large veins which
                                                       carry blood into the right side of the heart
   These are the blood vessels that carry the         Cardiovascular : Of or involving the heart
    oxygenated blood away from the heart.              and blood vessels
   It contains about 20% of blood at any one
    time.                                              Heart
   Their walls are thick and elastic.                 It is a muscular organ about the size of a
   They have small lumen (tubular cavities            closed fist that functions as the body’s
    inside).                                           circulatory pump.
   They also help to push the rapid flow of           It takes in deoxygenated blood through the
    blood when the ventricles are relaxed and          veins and delivers it to the lungs for
    the heart is refilling.                            oxygenation before pumping it into the various
   Arterioles are known as the small arteries.        arteries.
   It has a pulse and blood travels in spurts.