Question

13. How would valvular stenosis (narrowing) of the atrioventricular valves affect ejection of blood from the heart? sed on your understanding of heart and muscle function, why would it be necessary for a patient to be as still as possible while recording the ECG? 14. Ba

Answer 1

13) Our heart has four valves (Tricuspid valve,pulmonary valve,mitral valve and arotic valve) which helps in the flow of blood in the right direction. All these valves close and open during each heartbeat ( ''lub'' and ''dubb''). Stenosis of atrioventricular valve is the narrowing of tricuspid valve and bicuspid valve or mitral valve. Tricuspid stenosis i.e narrowing of heart's tricuspid valve prevents the blood flow between upper and lower part of the right side of the heart or we can say from right atrium to the right ventricle, where as narrowing of bicuspid valve (mitral stenosis) restricts the blood flow between left atrium to the left ventricle.

14) During ECG recording its important for a patient lie as still as possible because any movement like shivering or if we move our muscles will get constrict this can alter the results. In ECG we are recording heart's electrical signals only, so in order to avoid patient's skeletal muscles (those in arms and legs) signals we ask them to stay relax and this will help in avoiding to get unwanted recording and if we move the signals from muscles can interfere with the heart's signals because heart's muscles receive signals the same way the skeletal muscles receive signals.