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
a) Indicate the blood types possible from the mating of a male who is blood type O with a female of blood type AB. b) Could a female with blood type AB ever produce a child with bl

Which of the following best describes the tenants of Pangenesis Theory? A. The hereditary material is composed in every organ/tissue and is transmitted to the next generation b

Q. What is the significance of mitosis for the embryonic development? Every embryo grows from a single cell that bears mitosis and generates other cells that also divide themse

in what aspect are the cnidarians similar to protozoans? to the poriferans?

Autotomy and Regeneration Shedding of body parts in self-defense to avert the attention of the predator-enemy or in any other emergency is a type of autotomy (auto: self, tom

Define the Symptoms of Dry beriberi? Early symptoms are similar to those found in wet beriberi. The muscles become progressively wasted and weak and walking becomes difficult.

Neuroglia - Organisation of Nervous System We may refer neuroglia as the connective tissue of the nervous system. It involves all elements of the nervous system other than ne

Types of Cleavage a) Radial Type : If each of the blastomeres of upper tier lies exactly over the corresponding blastomeres of the lower tier the pattern of cleavage is radia

Define Energy and Protein requirements in geriatric nutrition? Decreased physical activity and changes in body composition and decreased basal metabolic rate affects the ma

Identify the abnormal protein and state how the abnormal protein affects the function of the tissue.