Blood group antigens are carbohydrates that are attached to proteins or lipids. An antigen is a substance foreign to the body that causes an immune response. An immune response occurs when antibodies, which are proteins in your immune system, are summoned to attack an antigen.
Blood that reaches the lungs travels throughout a network of small blood vessels, where oxygen moves into the blood and carbon dioxide moves out of the blood, according to the National Heart, Lung and Blood Institute.
Describe what happens to the blood as it leaves the small intestine. 1. The small intestine absorbs products or digestion 2. Nutrients molecules (and any toxins) travel in the hepatic portal vein to the liver. 3. Liver monitors blood content. 4. Blood enters general circulation by way of the hepatic vein.