Effects of Progesterone on the Uterine Lining. Progesterone plays an important part in the menstrual cycle. The menstrual cycle follows a precise pattern governed by the release of different hormones that interact with one another. Progesterone, whose production increases in the second half of the menstrual cycle, plays a pivotal part in preparing the uterine lining for implantation of an embryo. The corpus luteum, the remains of the ovulating follicle, produces progesterone after ovulation.
The pulmonary artery is the vessel transporting de-oxygenated blood from the right ventricle to the lungs. A common misconception is that all arteries carry oxygen-rich blood. It is more appropriate to classify arteries as vessels carrying blood away from the heart.
1 They have thicker walls than the atria, and they create higher blood pressures to pump blood out of the heart into circulation to the body and the lungs.  The right ventricle pumps deoxygenated blood into pulmonary circulation. The left ventricle pumps oxygenated blood into systemic circulation. The left ventricle is thicker because systemic circulation involves a much larger blood volume than pulmonary circulation.