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.
The pulmonary circuit carries blood to the lungs to be oxygenated and then back to the heart. In the lungs, carbon dioxide is removed from the blood, and oxygen taken up by the haemoglobin in the red blood cells. The systemic circuit carries blood around the body to deliver the oxygen and returns de-oxygenated blood to the heart. Blood also carries nutrients and waste.