STUDY OF THE EFFECT OFVARIOUSDRUGSANDIONSONTHE FROG'SHEART
STUDY OF THE EFFECT OF VARIOUS DRUGS AND IONS ON THE FROG’S HEART
THEORYIons1.The fluids perfusing the heart must contain aproper balance of the three essential ions i.e.sodium ions, potassium ions and calcium ions2. If these three ions are present properproportions, the heart is able to maintain itsincontractilityforhoursnormalanoxygenated environment.3. If the concentrations of ions are abnormal.then the heart will what happen?
THEORY Ions 1.The fluids perfusing the heart must contain a proper balance of the three essential ions i.e. sodium ions, potassium ions and calcium ions. 2. If these three ions are present proper proportions, the heart is able to maintain its normal contracti1ity for hours in an oxygenated environment. 3. If the concentrations of ions are abnormal, then the heart will what happen?
1). If concentration of these ions isaltered then heart rate andcontractility are changed.e.g. excess of potassium ions in thefluids perfusing the heart causesthe heart to become dilated andslows the heart rate and may stopheart during diastole
1). If concentration of these ions is altered then heart rate and contractility are changed. e.g. excess of potassium ions in the fluids perfusing the heart causes the heart to become dilated and slows the heart rate and may stop heart during diastole
2).An excess of sodium ionsdepresses cardiac function likepotassium ions excess but for anentirely different reason. Sodiumions compete with the calcium ionsat the same point in the excitatoryor contractile process of the heartmuscle
2).An excess of sodium ions depresses cardiac function like potassium ions excess but for an entirely different reason. Sodium ions compete with the calcium ions at the same point in the excitatory or contractile process of the heart muscle
3).Excess calcium ions in the fluidsenhance myocardial contractility .When large amount of calciumions are infused into theexperimental animals, the heartrelaxes less during diastole andeventually stops in systole(calcium rigor). A deficiency ofcalcium ions causes cardiacflaccidity
3).Excess calcium ions in the fluids enhance myocardial contractility . When large amount of calcium ions are infused into the experimental animals, the heart relaxes less during diastole and eventually stops in systole (calcium rigor). A deficiency of calcium ions causes cardiac flaccidity