McDonald's Airport Toys. While on the surface it sounds like a good idea: get an airplane as a toy and turn your Happy Meal box into the airport. However, when our clown-faced friend unveiled what has come to be known as the cheapest McDonald's toy of all time, kids were not excited.
Oxygen is carried in the blood in two forms: (1) dissolved in plasma and RBC water (about 2% of the total) and (2) reversibly bound to hemoglobin (about 98% of the total). At physiological PO2 (40 &#60; PO2 &#60; 100 mm Hg), only a small amount of oxygen is dissolved in plasma since oxygen has such a low solubility.
After your body's organs and tissues have used the oxygen in your blood, the vena cavae carry the oxygen-poor blood back to the right atrium of your heart. The superior vena cava carries oxygen-poor blood from the upper parts of your body, including your head, chest, arms, and neck.