Author Question: Heart beat (Read 815 times)

Perkypinki

  • Sr. Member
  • ****
  • Posts: 339
on: Dec 27, 2014
lub dub sound is produced when AV valves and semilunar valves get closed why no sound is produced when valves of heart open?



Celeste

  • Hero Member
  • Posts: 588
Reply #1 on: Dec 30, 2014
The moment intraventricular pressures exceed the pressure of the aorta and pulmonary artery, the aortic and pulmonic valves open.  Blood ejects into the aorta and the pulmonary artery from the respective left and right ventricles.  This results in a large decrease in ventricular volume and an increase in aortic pressure. At rest approximately 2/3 of the ventricle is ejected.

No heart sounds should occur during this phase as the opening of the valves upon ejection of the blood is silent.  If there is a sound then this may indicate a sign of valve disease or intracardiac shunts.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Cutaneous mucormycosis is a rare fungal infection that has been fatal in at least 29% of cases, and in as many as 83% of cases, depending on the patient's health prior to infection. It has occurred often after natural disasters such as tornados, and early treatment is essential.

Did you know?

Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.

Did you know?

Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.

Did you know?

The Food and Drug Administration has approved Risperdal, an adult antipsychotic drug, for the symptomatic treatment of irritability in children and adolescents with autism. The approval is the first for the use of a drug to treat behaviors associated with autism in children. These behaviors are included under the general heading of irritability and include aggression, deliberate self-injury, and temper tantrums.

Did you know?

Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.

For a complete list of videos, visit our video library