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.
Periods of anxiety trigger the release of hormones that cause increased heart rate and decreased blood vessel diameter, both of which lead to increased blood pressure. 1  The effect of stress on short term blood pressure can be dramatic, leading to mean arterial pressure increases of 30%-40%. These changes are short lived, though, with heart rate, blood vessel diameter, and blood pressure returning to normal as the hormones are eliminated.