pulmonary valve

Examples of pulmonary valve in the following topics:

• Heart Valve Disorders

  • Valvular heart disease includes aortic and mitral valve disorders, and pulmonary and tricuspid valve disorders.
  • Pulmonary and tricuspid valve diseases are right-side heart diseases.
  • Pulmonary valve diseases are the least common heart valve disease in adults.
  • The most common types of pulmonary valve diseases are: pulmonary valve insufficiency, pulmonary valve incompetence, and pulmonary valve regurgitation.
  • Both tricuspid and pulmonary valve diseases are less common than aortic or mitral valve diseases due to the lower pressure those valves experience.

• Operation of Semilunar Valves

  • When the atrioventricular valves shut, the semilunar valves open, forcing blood into the aorta and pulmonary artery.
  • The pulmonary valve (sometimes referred to as the pulmonic valve), which also has three cusps, separates the right ventricle from the pulmonary artery.
  • Similar to the aortic valve, the pulmonary valve opens in ventricular systole, when the pressure in the right ventricle exceeds the pressure in the pulmonary artery.
  • This anterior view of the heart indicates the semilunar valves, the aortic and pulmonary valves.
  • Describe the operation of the semilunar valves, the aortic and pulmonary valves

• Heart Sounds

  • The two major heart sounds are 'lub' (from the closure of AV-valves) and 'dub' (from the closure of aortic and pulmonary valves).
  • It is caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole.
  • S2 is split because aortic valve closure occurs before pulmonary valve closure.
  • During inspiration (breathing in) there is slightly increased blood return to the right side of the heart, which causes the pulmonary valve to stay open slightly longer than the aortic valve.
  • Due to this, the naming convention is to divide the second sound into two second sounds, A2 (aortic), and P2 (pulmonary).

• Fibrous Skeleton of the Heart

  • The aortic ring: encircles the aortic valve.
  • The pulmonary ring: encircles the pulmonary valve.
  • Similarly to the aortic ring, the pulmonary ring provides structural support for the pulmonary valve.
  • The left fibrous ring: encircles the bicuspid valve.
  • The right fibrous ring: encircles the tricuspid valve.

• Blood Flow in the Lungs

  • The pulmonary circulatory system is the portion of the cardiovascular system in which oxygen-depleted blood is pumped away from the heart to the lungs, via the pulmonary artery.
  • Oxygenated blood is then returned to the heart via the pulmonary vein.
  • From the right ventricle of the heart, blood is pumped through the pulmonary semilunar valve into the left and right pulmonary arteries (one for each lung) and travels through the lungs.
  • The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left atrium of the heart, completing the pulmonary cycle.
  • This blood is then pumped through the bicuspid valve into the left ventricle.

• Systemic and Pulmonary Circulation

  • The blood is then pumped through the tricuspid valve into the right ventricle.
  • From the right ventricle, blood is pumped through the pulmonary valve and into the pulmonary artery.
  • Once entering the left heart, the blood flows through the bicuspid valve into the left ventricle.
  • From the left ventricle, the blood is pumped through the aortic valve into the aorta to travel through systemic circulation, delivering oxygenated blood to the body before returning again to the pulmonary circulation.
  • The blood is then pumped through the mitral valve into the left ventricle.

• Blood Supply to the Lungs

  • The vena cava fills the right atrium with blood, which then ejects blood into the right ventricle by passing through the tricuspid valve.
  • After blood fills in the right ventricle, it contracts and pumps the blood through the pulmonary valve, and into the pulmonary arteries.
  • This blood then enters and fills inside the left atrium, which pumps it through the mitral valve (also called bicuspid) into the left ventricle.
  • The blood fills inside the left ventricle and is then pumped through the aortic valve into the aorta, which marks the beginning of systemic circulation.
  • Diagram of pulmonary circulation.

• Great Vessels of the Heart

  • The venae cavae are not separated from the right atrium by valves.
  • Blood is pumped from the left ventricle through the aortic valve, into the aorta.
  • When the left ventricle contracts to force blood through the aortic valve into the aorta, the aorta expands.
  • Blood first passes through the pulmonary valve as it is ejected into the pulmonary arteries.
  • The pulmonary arteries and veins are both considered to be part of pulmonary circulation.

• Structures of the Heart

  • After blood passes through the pulmonary arteries, the right semilunar valves close, preventing the blood from flowing backwards into the right ventricle.
  • The valve separating the chambers on the left side of the heart is called the biscuspid or mitral valve (left atrioventricular valve).The blood passes through the bicuspid valve to the left ventricle where it is pumped out through the aorta, the major artery of the body, taking oxygenated blood to the organs and muscles of the body.
  • Once blood is pumped out of the left ventricle and into the aorta, the aortic semilunar valve (or aortic valve) closes, preventing blood from flowing backward into the left ventricle.
  • One-way valves separate the four chambers.
  • Blood then enters the pulmonary circuit and is oxygenated by the lungs.

• Pumps and the Heart

  • The septum divides the left and right side of the heart, while the valves of the heart ensure that blood only flows in one direction.They include the tricuspid valve-found between the right atrium and the right ventricle-and the mitral valve-found between the left atrium and the left ventricle.
  • The list of heart valves also includes the semi-lunar valves, which are located at the bottom of the aorta and pulmonary artery.
  • Strong tendinous chords attached to valves prevent them from turning inside out when they close.
  • The heart beat can be heard as a sound that the valves make when they close.
  • The ‘lub' sound is made when the atrio ventricular valves close and the ‘dub' sound is made when the semi lunar valves close.