An immune response occurs when antibodies, which are proteins in your immune system, are summoned to attack an antigen. When you say you are blood type A, what you are telling people is that the cells in your body make antibodies only to type B antigens.
Best Answer: Blood pressure elevates when the arterioles constrict, which increases the volume carried in the larger arteries, which increases the pressure exerted against the interior walls of those arteries.When vessels constrict, they tighten, and reduce the amount of space inside.ee constrict think choke. Constricting arteries mean the diameter of the hollow part of the arteries where the blood flows is getting smaller. This generally increase blood pressure. When the blood vessel dilates, the diameter increases, lowering blood pressure.
High blood pressure, or hypertension, occurs when your blood pressure is 140/90 most of the time, according to PubMed Health. Blood pressure measures the force against the artery walls as your blood is circulated through your body. Many things can affect the numbers, including heredity, illness, nutrition and hormones.