Describe what happens when SA node fails?
Answers
The blood from the upper portion of the body enter the heart from the superior vena cava and the blood from lower portion of the body enter the heart from the inferior venacava. The blood after entering both the vena cava travels to right atrium as the right atrium receives both the openings of the superior venacava and the inferior venacava. The opening on the inferior vena cava is guarded by Eustachian valve. The opening on the coronary sinus has coronary or Thebasian valve. The coronary sinus carries the most of the blood from the heart itself. All the coronary veins open into the coronary sinus. The blood from the right atrium is pushed into the right ventricle and the tricuspid valve prevents the back flow of blood from right ventricle to the right atrium. Then the deoxygenated blood from the right ventricle is pumped out of the heart through left pulmonary artery and right pulmonary artery for oxidation into the lungs. Then the Pulmonary semilunar valves prevents the back flow of deoxygenated blood from the right pulmonary artery and left pulmonary artery to the right ventricle. After oxidation the blood enters the heart through Left Pulmonary Veins into the left atrium . Then the blood from the left atrium enters the left ventricle. The Arotic Semilunar Valves prevents the back flow of blood from the left ventricle towards the left atrium. The blood from the left ventricle is pumped out of the heart through the Aorta. The Aortic Semilunar Valves prevents the back flow of blood from Aorta to the left ventricle. The oxygenated blood from the artery travels through brachiocephalic artery,left common carotid artery and left subclavian artery to the upper portion of the body and delever oxygen for cellular respiration. The process of sending deoxygenated blood to the lungs and the process of sending oxygenated blood from lungs to the rest of the body is done by heart in one systole(contraction phase) and one diastole (relaxation phase) . One heart beat consist of one systole and one diastole . In humans the heart beat originates in the sinoatrial node (SA Node) – Pace maker which lies in the wall of the right autrium near the opening of the superior vena cava . The SA node is a mass of neuromascular tissue . If SA node fails then the heart will stop working and the above mentioned processes will stop.
please mark me brainliest please