The action research process is an interactive method of collecting information. In the field of education, action research is used quite often to explore new ways of teaching and interacting in the classroom.
Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries donât require valves because pressure from the heart is so strong that blood is only able to flow in one direction.) Valves also help blood travel back to the heart against the force of gravity.rteries carry oxygenated blood away from the heart. Theyâre tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily. Arteries also contain a strong, muscular middle layer that helps pump blood through the body.
Coronary artery disease (CAD) is a complex disease that causes reduced or absent blood flow in one or more of the arteries that encircle and supply the heart.The disease may be focal or diffuse.ltrasonography. Echocardiography can be used to identify the left main coronary artery. In some patients, much of the RCA and LAD can be viewed; however, in most patients, the imaging window is inadequate for useful coronary imaging from outside the chest.