Cardiac_Mechanics

Cardiac Mechanics Abstract: The purpose of this experiment was to subject a rat cardiac muscle to different physiological situations and determine their effect on the twitch force and duration. Force-frequency relation show a positive trend suggesting that as frequency of stimulation increases (for the range of 0.2-0.8 Hz), the force increases. Also the extra cellular calcium concentration effects on the peak force were measured, showed an increasing trend when the [Ca2+ ]o was incrementally increased from 0.2 to 3mmolL-1. The rat cardiac muscle was also subjected to cardiac glycoside such as ouabain, which resulted in an increase in the diastolic force, inotropic agents such as isoprenaline, which increased the velocity of contractility, and finally the effects of caffeine were considered. Method: Experimental set up: We were provided with a ventricular strip of a rat heart muscle; it had the dimensions of (~20mm resting length, 5mm wide and 1mm thick). The strip was embedded in an oxygenated 1.5mM Ca2+ Tyrode solution (constant PH=7.4) with constant O2 partial pressure of oxygen is 760 mmHg, because the cell needs oxygen in order to survive, the strip mounted using threads to a force transducer and a stimulator (REF1), these were connected to power LAB (amplifier) which was force, muscle, increase, frequency, calcium, half, twitch, increases, width, relation, peak, isoprenaline, stimulation, rat, mmoll-1, contraction, cardiac, caffeine, ouabain, experiment, concentration, [ca2, steady, results, response, increased, extra, cellular, because, ]o, time, increasing, effect, ca2, aliquot