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
Describe two pieces of evidence indicating that speciation does not always occur at the same rate. Some species of moths on the Hawaiian Islands appear to have evolved during t

Determine requirements of Vitamins at high altitude? It is observed that requirement of vitamins is not different as compared to plains. In humans, exposure to high altitude ha

Augmentation Therapy: The functional gene is introduced in addition to the defective gene endogeneous to the cell(s) in this somatic cell gene therapy,  i.e. the improved  cell

Placement of the Implant in an Infected Socket or a Pathologic Lesion Dental implants may fail due to: 1) Placement of the implant fixture into an infected socket (during im

Which of the following statements regarding the separation of DNA fragments using gel electrophoresis is false? A. DNA fragments will migrate towards the positively charged ele

description on characteristics of pisces fish

Digestion The nutritional requirements and the various ways used by heterotrophic organisms to obtain nutrition. Whether food is used to give energy or to build the body, the

Q. Monounsaturated fatty acids required for dyslipidemia? Polyunsaturated fatty acids also have a cholesterol decreasing effect. Omega 3 fatty acids are excellent for the heart

Explain Theory or Principle of Determination of Coliforms? Coliforms are gram negative, non-spore forming, facultative anaerobic bacteria which produce acid and gas on lactose

What Factors causing short-term changes in intra-ocular pressure 1) Arterial blood pressure 2) Systemic venous pressure (SVP) 3) Mechanical pressure 4) Plasma osmolari