For many true experimental designs, pretest-posttest designs are the preferred method to compare participant groups and measure the degree of change occurring as a result of treatments or interventions.
Itâs important to note that the flush caused by niacin is not harmful or dangerous. It is actually a sign of improved blood flow and circulation. Also niacin oxygenates the blood. When you get a niacin âflushâ it is an indication that the niacin is causing small blood vessels in your body to expand in size.Many of your small blood vessels, called capillaries, are so small that blood cells can only go through them in single file or if they are flexible enough to fold over.t is actually a sign of improved blood flow and circulation. Also niacin oxygenates the blood. When you get a niacin âflushâ it is an indication that the niacin is causing small blood vessels in your body to expand in size.
Report Abuse. Definitely the Aorta. The Aorta is the largest artery in the body, and it carries blood directly out of the heart. Capillaries are the smallest blood vessels in the body, and they are close to the skin.You know when you get a paper cut-the blood you see comes from the capillaries.Tiny amounts of blood, because they are so small and don't have a lot of pressure.apillaries are the smallest blood vessels in the body, and they are close to the skin. You know when you get a paper cut-the blood you see comes from the capillaries. Tiny amounts of blood, because they are so small and don't have a lot of pressure.