How is heart activity controlled in terms of stimulus, receptor, co-ordinator, effector and response?

Answer 1

heart rate is dominated by parasympathetic control esp on atria - although sympathetic control to both atria and ventricles can be overridden by both adrenaline and noradrenaline. Heart rate will increase as end-diastolic volume increases thus output will increase and the converse is true. EDV affected by exercise, metabolites downstream that increase dilation of vessels which has effect on volume entering leaving heart, breathing rate (venous return via muscular and thoracic pump). Best to read a textbook!!

Answer 2

When a stimulus comes in, it would be received by the receptor. The receptor would then send signal to the co-ordinator to adjust the heart activity (response) and the heart (effector) would pump at that rate.