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.
What does the left ventricle do? The left ventricle is separated from the aorta by the aortic valve, which prevents blood from flowing back into the ventricle with each contraction. As an artery, the aorta moves blood away from the heart toward the rest of the body. Oxygenated blood travels through the aorta to provide nourishment to the body's tissues. The right ventricle pumps blood only to the lungs. The left ventricle, therefore, has thicker walls than the right because it needs to pump blood to all the organs. This generates the high blood pressure found in the aorta.