![\"\"](\"https:\/\/meddists.com\/learn\/wp-content\/uploads\/2021\/10\/valves-heart-1024x986.png\")
Description<\/h3>\n<\/span>\n\n\nThe heart is equipped with two sets of valves. These are the cuspid <\/strong>and semilunar valves<\/strong>.<\/p>\n\n\n\n- The cuspid valves are found between the atria and ventricles (they are the atrioventricular valves<\/strong>).<\/li>
- The semilunar valves are found between the ventricles and the major vessels (aorta, and pulmonary trunk)<\/li><\/ul>\n\n\n<\/span>\n
Cuspid valves<\/h3>\n<\/span>\n\n\nThe cuspid valves are found between the atria and ventricles (atrioventricular valves).<\/p>\n\n\n\n
The left atrioventricular valve has three cusps (hence, it is called tricuspid<\/strong>), while the right atrioventricular valve has two cusps (bicuspid<\/strong> or mitral valve<\/strong>, as it resembles a Bishop\u2019s miter<\/span>; see Figure 3).<\/p>\n\n\n\n- On the right side (between the right atrium and ventricle) \u2014 tricuspid valves<\/strong><\/li>
- On the left side (between the left atrium and ventricle) \u2014 bicuspid\/mitral valve<\/strong> (mitral as it resembles a Bishop\u2019s miter)<\/li>
- The valves consist of fibrous tissue covered by mesothelium.<\/li>
- They are attached to the rings of the fibrous skeleton of the heart<\/a> superiorly and are anchored to the papillary muscles <\/strong>through non-elasstic tendinous cords (chordae tendineae<\/strong>) inferiorly.<\/li>
- The cuspid valves are open during the diastolic phase<\/strong>, and closed during the systolic phase<\/strong>.<\/li><\/ul>\n\n\n\n\n<\/span>\n
Tricuspid valve<\/h4>\n<\/span>\n\n\nThe tricuspid valve has three cusps:<\/p>\n\n\n\n
- Anterior cusp<\/strong><\/li>
- Posterior cusp<\/strong><\/li>
- Septal cusp<\/strong><\/li><\/ul>\n\n\n\n
The tricuspid valve is anchored to 3 papillary muscles<\/strong>, attached to two cusps each through the chordae tendineae:<\/p>\n\n\n\n- Anterior papillary muscle<\/strong> \u2014 the largest, anchors the anterior and posterior cusps<\/li>
- Posterior papillary muscle<\/strong> \u2014 smaller than the anterior muscle, connects to the posterior and septal cusps<\/li>
- Septal papillary muscle<\/strong> \u2014 arises at the inter-ventricular septum, connects to the anterior and septal cusps<\/li><\/ul>\n\n\n\n
The chordae tendineae function to pull the cusps when the papillary muscle contract hence opening the valve, maintain the position of the cusps, and maintain the potency of the valve during diastole.<\/p>\n\n\n<\/span>\nBicuspid valve<\/h4>\n<\/span>\n\n\n- The bicuspid valve has only 2 cusps<\/strong>: anterior <\/strong>and posterior cusp<\/strong>.<\/li>
- The two cusps attach to two papillary muscles (anterior and posterior papillary muscles) through the chordae tendineae, just like the tricuspid valve<\/li><\/ul>\n<\/div>\n\n\n\n\n
![\"\"](\"http:\/\/meddists.com\/wp-content\/uploads\/2018\/09\/Muscolopapillarecordetendinee.jpg\")
<\/a>Figure 2. Chordae tendineae<\/strong> (Credit: E.Faccio P.Saccheri, CC BY-SA 2.5)<\/figcaption><\/figure><\/div>\n\n\n\n![\"\"\/](\"https:\/\/meddists.com\/wp-content\/uploads\/2018\/09\/Screen-Shot-2018-09-01-at-14.46.48.png\")
<\/a>Figure 3. Bishop\u2019s miter<\/strong><\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n<\/span>\nSemilunar valves<\/h3>\n<\/span>\n\n\nThe semilunar valves are formed by three cup-shaped flaps which open under pressure in an umbrella-like fashion, separating between the ventricles and the large arteries (aorta and pulmonary trunk).<\/p>\n\n\n\n
The two semilunar valves are therefore the aortic <\/strong>and pulmonary valves:<\/strong><\/p>\n\n\n\n- Due to embryological reasons, both valves have the right and left flaps, while the valve of the aorta has a posterior <\/strong>flap, and the pulmonary valve has an anterior<\/strong> flap<\/li>
- Each valve consists of 3 pars flaccidae, 3 pars tensa, 3 nodules, and 6 lunulae<\/strong>, with a one nodule, one pars flaccida, one pars tensa, and two lunulae on each flap (see Figure 4).
- The nodulus<\/strong> is located centrally on the pars flaccida<\/strong>, dividing it into two lunulae<\/strong><\/li>
- The \u201cpocket\u201d itself at its bottom is sealed by the pars tensa<\/strong><\/li>
- Above the valve of the aorta, there is a dilated part of the aorta which is known as the aortic sinus<\/strong>
- The aortic sinus contains the orifices of the coronary arteries <\/strong>(above the right and left flaps)<\/li>
- This dilated part from outside is known as the bulb<\/strong><\/li><\/ul><\/li><\/ul><\/li>
- The semilunar valves are closed during the diastolic phase<\/strong> and open during the systolic phase<\/strong>.<\/li>
- During the systolic phase, the blood goes out from the ventricles into the aortic arch and the pulmonary trunk.<\/li>
- In the diastolic phase, the blood pressure pushes the flaps to open, like an umbrella, resulting in the closure of the orifice, preventing regurgitation<\/li>
- During the diastolic phase, as a result of the closing of the aortic valve, blood enters into the coronary sinus, supplying the heart.<\/li><\/ul>\n\n\n\n
- The cuspid valves are found between the atria and ventricles (they are the atrioventricular valves<\/strong>).<\/li>
- The semilunar valves are found between the ventricles and the major vessels (aorta, and pulmonary trunk)<\/li><\/ul>\n\n\n<\/span>\n
Cuspid valves<\/h3>\n<\/span>\n\n\n
The cuspid valves are found between the atria and ventricles (atrioventricular valves).<\/p>\n\n\n\n
The left atrioventricular valve has three cusps (hence, it is called tricuspid<\/strong>), while the right atrioventricular valve has two cusps (bicuspid<\/strong> or mitral valve<\/strong>, as it resembles a Bishop\u2019s miter<\/span>; see Figure 3).<\/p>\n\n\n\n
- On the right side (between the right atrium and ventricle) \u2014 tricuspid valves<\/strong><\/li>
- On the left side (between the left atrium and ventricle) \u2014 bicuspid\/mitral valve<\/strong> (mitral as it resembles a Bishop\u2019s miter)<\/li>
- The valves consist of fibrous tissue covered by mesothelium.<\/li>
- They are attached to the rings of the fibrous skeleton of the heart<\/a> superiorly and are anchored to the papillary muscles <\/strong>through non-elasstic tendinous cords (chordae tendineae<\/strong>) inferiorly.<\/li>
- The cuspid valves are open during the diastolic phase<\/strong>, and closed during the systolic phase<\/strong>.<\/li><\/ul>\n\n\n\n
\n<\/span>\nTricuspid valve<\/h4>\n<\/span>\n\n\n
The tricuspid valve has three cusps:<\/p>\n\n\n\n
- Anterior cusp<\/strong><\/li>
- Posterior cusp<\/strong><\/li>
- Septal cusp<\/strong><\/li><\/ul>\n\n\n\n
The tricuspid valve is anchored to 3 papillary muscles<\/strong>, attached to two cusps each through the chordae tendineae:<\/p>\n\n\n\n
- Anterior papillary muscle<\/strong> \u2014 the largest, anchors the anterior and posterior cusps<\/li>
- Posterior papillary muscle<\/strong> \u2014 smaller than the anterior muscle, connects to the posterior and septal cusps<\/li>
- Septal papillary muscle<\/strong> \u2014 arises at the inter-ventricular septum, connects to the anterior and septal cusps<\/li><\/ul>\n\n\n\n
The chordae tendineae function to pull the cusps when the papillary muscle contract hence opening the valve, maintain the position of the cusps, and maintain the potency of the valve during diastole.<\/p>\n\n\n<\/span>\n
Bicuspid valve<\/h4>\n<\/span>\n\n\n
- The bicuspid valve has only 2 cusps<\/strong>: anterior <\/strong>and posterior cusp<\/strong>.<\/li>
- The two cusps attach to two papillary muscles (anterior and posterior papillary muscles) through the chordae tendineae, just like the tricuspid valve<\/li><\/ul>\n<\/div>\n\n\n\n
\n<\/a>Figure 2. Chordae tendineae<\/strong> (Credit: E.Faccio P.Saccheri, CC BY-SA 2.5)<\/figcaption><\/figure><\/div>\n\n\n\n <\/a>Figure 3. Bishop\u2019s miter<\/strong><\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n<\/span>\n Semilunar valves<\/h3>\n<\/span>\n\n\n
The semilunar valves are formed by three cup-shaped flaps which open under pressure in an umbrella-like fashion, separating between the ventricles and the large arteries (aorta and pulmonary trunk).<\/p>\n\n\n\n
The two semilunar valves are therefore the aortic <\/strong>and pulmonary valves:<\/strong><\/p>\n\n\n\n
- Due to embryological reasons, both valves have the right and left flaps, while the valve of the aorta has a posterior <\/strong>flap, and the pulmonary valve has an anterior<\/strong> flap<\/li>
- Each valve consists of 3 pars flaccidae, 3 pars tensa, 3 nodules, and 6 lunulae<\/strong>, with a one nodule, one pars flaccida, one pars tensa, and two lunulae on each flap (see Figure 4).
- The nodulus<\/strong> is located centrally on the pars flaccida<\/strong>, dividing it into two lunulae<\/strong><\/li>
- The \u201cpocket\u201d itself at its bottom is sealed by the pars tensa<\/strong><\/li>
- Above the valve of the aorta, there is a dilated part of the aorta which is known as the aortic sinus<\/strong>
- The aortic sinus contains the orifices of the coronary arteries <\/strong>(above the right and left flaps)<\/li>
- This dilated part from outside is known as the bulb<\/strong><\/li><\/ul><\/li><\/ul><\/li>
- The semilunar valves are closed during the diastolic phase<\/strong> and open during the systolic phase<\/strong>.<\/li>
- During the systolic phase, the blood goes out from the ventricles into the aortic arch and the pulmonary trunk.<\/li>
- In the diastolic phase, the blood pressure pushes the flaps to open, like an umbrella, resulting in the closure of the orifice, preventing regurgitation<\/li>
- During the diastolic phase, as a result of the closing of the aortic valve, blood enters into the coronary sinus, supplying the heart.<\/li><\/ul>\n\n\n\n
- This dilated part from outside is known as the bulb<\/strong><\/li><\/ul><\/li><\/ul><\/li>
- The \u201cpocket\u201d itself at its bottom is sealed by the pars tensa<\/strong><\/li>
- Each valve consists of 3 pars flaccidae, 3 pars tensa, 3 nodules, and 6 lunulae<\/strong>, with a one nodule, one pars flaccida, one pars tensa, and two lunulae on each flap (see Figure 4).
- The two cusps attach to two papillary muscles (anterior and posterior papillary muscles) through the chordae tendineae, just like the tricuspid valve<\/li><\/ul>\n<\/div>\n\n\n\n
- Posterior papillary muscle<\/strong> \u2014 smaller than the anterior muscle, connects to the posterior and septal cusps<\/li>
- Posterior cusp<\/strong><\/li>
- On the left side (between the left atrium and ventricle) \u2014 bicuspid\/mitral valve<\/strong> (mitral as it resembles a Bishop\u2019s miter)<\/li>
- The semilunar valves are found between the ventricles and the major vessels (aorta, and pulmonary trunk)<\/li><\/ul>\n\n\n<\/span>\n
![\"\"](\"https:\/\/meddists.com\/learn\/wp-content\/uploads\/2022\/01\/aorta_left_ventricle_cut.png\")
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