Final Edited path that blood takes through heart
| Steps |
|---|
| Deoxygenated Blood from body - returned to right atrium by 2 large veins ⇒ Venae Cavae Upper vena cava: transports blood from head, neck, arms back to the right atrium. Lower vena cava: Transports blood from rest of the body (excluding lungs) back to the right atrium |
| As right atrium muscles contract ⇒ blood is forced into the right ventricle. → Tricuspid valve between the right atrium and right ventricle ⇒ opens when blood pressure in the right ventricle is lower than that in the right atrium. ⇒ tricuspid valve consists of 3 flaps that point downward into the right ventricle. ⇒ these flaps are attached to the walls of the right ventricle by cord like tendons ⇒ Chordae Tendineae. |
| When muscles of the right ventricle contract ⇒ blood pressure forces the flaps of the tricuspid valve to close. - Closure of the valve prevents backflow of blood into the atrium. - Chordae tendineae prevents the flaps from being reverted into the atrium when the muscles of the right ventricle contract. |
| From the right ventricle ⇒ blood leaves the heart by pulmonary arteries to the lungs. ⇒ Semilunar valves in the pulmonary vein (pulmonary valve) prevent backflow of blood from pulmonary artery back into the right ventricle. ⇒ Blood in pulmonary arteries is at lower pressure than blood in the aorta. Low pressure reduces the rate of blood flow in pulmonary arteries to give more time for gaseous exchange in the lungs |
| Pulmonary veins ⇒ transports oxygenated blood from the lungs to the left atrium. - When muscles of the left atrium contract, blood pressure in the left atrium becomes higher than pressure in the left ventricle. - High pressure will force an open bicuspid valve that separates the left atrium from the left ventricle. Allows blood to enter the left ventricle. - Bicuspid valve is similar to tricuspid valve in structure and function ⇒ but it has 2 flaps not 3. |
| Blood passes from the left atrium ⇒ Through the bicuspid valve ⇒ into the left ventricle. Bicuspid valve has 2 flaps that point down into the left ventricle. Chordae Tendineae ⇒ prevent flaps from being reverted into the atria when the left ventricle muscles contract.** |
| Muscles of the left ventricle contract ⇒ blood leaves through the aorta. - Blood is distributed to all parts of the body except for the lungs - Aorta possesses semilunar valves called aortic valve ⇒ prevent backflow of blood into the left ventricle. - Blood enters the aorta at a very high pressure. 2 small coronary arteries ⇒ emerge from the aorta. ⇒ brings oxygen and nutrients to the heart muscles/cardiac muscles. |
What Happens when there is a hole in the heart → hole may be present in median septum separating left and right atria or left and right ventricles. blood will flow through the hole mostly from the left side of the heart to the right side > because pressure on left side is much higher. → results in the mixing of deoxygenated blood → which causes less oxygen to be transported to body cells for respiration.
patients with this condition → may suffer from shortness of breath, fatigue, and in serious cases heart failure may occur.