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.
Blood is conveyed from the pulmonary trunk to the left and right pulmonary arteries. Pulmonary Arteries. The main pulmonary artery extends from the heart and branches into a right vessel and a left vessel. Right Pulmonary Artery (RPA): directs blood to the right lung. Extending from the pulmonary trunk, it dips under the aortic arch and behind the superior vena cava to the right lung. The RPA branches into smaller vessels within the lung. Left Pulmonary Artery (LPA): directs blood to the left lung.