Valves of the heart, Biology

Valves of the Heart

There are four valves which are flap-like structures that function to maintain unidirectional (forward) blood flow through the heart chambers. These valves open and close in response to pressure and volume changes within the cardiac chambers. There are two atrio-ventricular valves which separate the atria from the ventricles and two semi-lunar valves which separate the pulmonary artery and the aorta form their respective ventricles.

Atrio-ventricular valves are the tricuspid and bicuspid (mitral) valves. The tricuspid valve located between the right atrium and right ventricle contain three leaflets held in place by fibrous cords called chordae tendinae. The chordae tendinae in turn are anchored to the ventricular wall by the papillary muscles.

The bicuspid or the mitral valve located between the left atrium and left ventricle has two valve cusps or leaflets. It is attached in the same manner as the tricuspid valve. The chordae tendinae support the valves during ventricular systole to prevent valvular porlapse into the atrium. Damage to the chordae tendinae or to the papillary muscles would permit blood to regurgitate into the atrium during ventricular systole. AV valves are closed during ventricular systole and open during ventricular diastole.

The semi-lunar valves consist of three cup-like cusps. They lie between each ventricle and the great vessels into which it empties. These valves can open during ventricular systole to permit blood flow into aorta and pulmonary artery and closed during diastole to prevent retrogarde flow form the aorta of pulmonary artery back into the ventricles when it is relaxed.

 

Posted Date: 10/30/2012 5:48:20 AM | Location : United States







Related Discussions:- Valves of the heart, Assignment Help, Ask Question on Valves of the heart, Get Answer, Expert's Help, Valves of the heart Discussions

Write discussion on Valves of the heart
Your posts are moderated
Related Questions

Define the Carbohydrate Utilization Pattern Test? Carbohydrates are composed of carbon, hydrogen and oxygen. These organic molecules are catabolized by large number of microorg

Examination is begun by placing the transducer in left parasternal region, usually in the third or fourth left intercostal space. From this position, a sector image of the heart

Chlorophyll Chlorophyll, the pigment responsible for giving bright green colour to the vegetables, is very unstable and undergoes changes in colour which are often considered t


Q Does RNA molecule have two polynucleotide chains like the DNA? Only DNA has two polynucleotide chains. The RNA is formed by just one polynucleotide chain.

A monohybrid cross: A.Determines the genetic makeup of an organism B.always involves homozygous alleles. C.always involves organisms that are heterozygous at all loci. D.Always inv

What is the difference between essential and natural amino acids? Ans) Significant amino acids are those that the organism is not able to synthesize and that require to be inges

Preparation of ICU Cardiac surgical ICU is generally connected to the operation theatre so that the patient can be wheeled into the ICU after surgery and also to wheel back

Explain the Principles of Taxonomy? The goal of taxonomy is to develop a workable classification that reflects evolutionary relationships and provides identification and no