The aortic and pulmonic valves are located between the ventricles and the major blood vessels leaving the heart. Both sides of the heart pump blood at the same time. As the right ventricle contracts and sends blood to the lungs, the left ventricle also contracts and squeezes blood out to the body. The heart’s cycle of activity has two stages Systole and Diastole.
Systole occurs when the ventricles contract.
Diastole is the stage when the ventricles relax and the atria contract.
One complete cycle of contraction and relaxation called a cardiac cycle. It makes up one heartbeat during each cardiac cycle. The heart valves open and closes. Closing of the valves produces most of the ‘lub dub’ sound of a heartbeat, which doctors can hear with an instrument called a stethoscope.
As the ventricles contract, the mitral and tricuspid valves close, causing the first sound.
- Immediately after the valves, close pressure in the ventricles forces the aortic pulmonic valves to open.
- After a contraction ends, pressure in the ventricles drops.
- The aortic and pulmonic valves then close, causing most of the second heart sound.
The human heart has four valves that pump blood in and out of the heart. The aortic and pulmonic valves or semilunar valves are located between the ventricular outflow tract and the ascending aorta. The other two valves are mitral and tricuspid valves. It is the final structure of the heart that the blood travels through prior to stopping the flow during the systemic circulation.
This valve has three cusps known as the left coronary artery, right coronary artery, and non-coronary cusp. Sometimes they are also termed as a left, right, and posterior cusp.
The three cusps, once the valve is shut, include a sinus termed an aortic sinus of Valsalva. The source of the coronary artery is in two of these cusps. The sinuses in cross-section’s diameter are broader than the aorta in the left ventricular outflow tract. The joining of aorta and sinuses is known as the sinotubular junction. The valve lays posterior to the pulmonary valve at which the two cusps connect points below the valve together. It is these two sinuses that contain the origin of the coronary arteries.
The pressure in the left ventricle increases with contraction. When this pressure in the left ventricle is more than the aorta, at that point, the aorta valve opens. It makes blood flow from the left ventricle to aorta. The close of the aortic valve leads the next heart sound (S2).
Closure of the valve allows high pressure in the systemic circulation, at the same time, reduce pressure in the left ventricle. It maintains the flow of blood circulation from the lungs to the left ventricle. Reduction of the functioning of the valve leads to a loss in diastolic blood pressure and acute aortic insufficiency causing wide bounding pulses. The endocardium perfuses through diastole, and intense insufficiency can lessen perfusion of the center. Therefore, pulmonary edema and heart failure may happen.
Gradually worsening aortic insufficiency leads to a chronic insufficiency allowing the heart to compensate (unlike severe insufficiency).
The pulmonary valve is your semilunar valve of the heart. It is located between the right ventricle and the pulmonary artery. Like the aortic valve, it also opens in ventricular systole, once the pressure in the right ventricle increases more than in the artery. At the end of the ventricular systole, once the pressure in the right ventricle falls, the valve wills shut.
It allows blood to flow from the right ventricle to the lungs (through the pulmonary artery). Here, the blood will receive oxygen.
It is safeguarded from three semilunar cusps – 2 in the front and one behind. The edge of every cusp introduces a nodule of the semilunar cusp in the middle of the lunule of the semilunar cusp, with two slender sections. Every cusp forms pocket such as dilatation termed pulmonary sinus in the first part of the pulmonary trunk.
The Aortic And Pulmonic Valves in Heart
The heart of an average person at rest beats 60 to 80 times each minute. Each beat sends about 2 ½ ounces of blood out of each ventricle. It means that at rest, the heart pumps the same 2 ½ gallons of blood each minute.