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.
Vasoconstriction. 1  There are muscles around all the major arteries of our body that automatically constrict or relax in order to decrease or increase blood flow. This allows the body to send more blood and warmth to the critical organs of your body (like the heart, lungs and brain), temporarily decreasing the blood flow to your hands and feet. Cold hand diseases that occur from vasoconstriction happen when these muscles apply pressure to the arteries for too long, which decreases blood flow.