Deoxygenated blood from the neck, head and arms will flow from the Anterior Vena Cava into the right atrium of the heart. The Posterior Vena Cava will collect deoxygenated blood from the renal veins of the kidney and hepatic veins of the liver and the blood will also flow into the right atrium. The blood pressure in the right atrium is now higher than the blood pressure in the right ventricle, thus causing the tricuspid valve to open. The tricuspid valve has 3 flaps which are attached to the right ventricle by Chordae Tendineae. They point downwards to allow easy blood flow from the right atrium into the right ventricle. Since blood has flowed from the right atrium into the right ventricle, blood pressure in the right ventricle is now higher than the right atrium, thus causing the tricuspid valve to close to prevent backflow of blood into the right atrium. The higher blood pressure in the right ventricle also causes the semi-lunar valve of the pulmonary arch to open. Blood then flows into the pulmonary arch and the semi-lunar vale then closes, preventing backflow of blood into the right ventricle. The pulmonary arch leaves the heart and divides into two pulmonary arteries, each leading to each lung.
The blood pressure is lower in the aorta nearer to the lungs than when it was leaving the heart. This allows sufficient time for gaseous exchange and for the blood to be well oxygenated. The oxygenated blood is then transported by pulmonary veins into the left atrium. The left atrium now has a higher blood pressure than the left ventricle, thus forcing open the bicuspid valve. The bicuspid valve has 2 flaps and its structure and function is similar to the tricuspid valve. Blood flows into the left ventricle and the blood pressure is not higher in the left ventricle, thus causing the bicuspid valve to close, preventing backflow of blood into the left atrium. The high blood pressure in the left ventricle also causes the semi-lunar valve in the aortic arch to open, allowing blood to flow into it. It then closes and prevent backflow of blood into the left ventricle. The aortic arch split into 2 parts, one is the artery to the head, neck and arm. The other is that the aortic arch curls backwards to the left side of the heart and continues posteriorly as the dorsal aorta. The dorsal aorta distributes oxygenated blood through the arteries to the stomach and intestines, through the renal arteries to the kidney and through the hepatic artery to the liver and arteries to other parts of the body. Also, two small ateries called the coronary ateries emerge from the aortic arch to provide nutrients and oxygen to the heart muscles.
Ventricular Systole is the process when the ventricles contract and Ventricular Diastole is the process when the ventricles relax, 1 Ventricular Systole and 1 Ventricular Diastole forms a heatbeat. A normal heatrate is 0.8 sec per beat.
Ok that is just all about the structure of the heart. Ok thats all!! KK see ya!!
