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IntroductionPericardiumis the thin membrane surrounding the heart

Amphibian Ringers Solutionaqueous solution of the chlorides of sodium, potassium, and calcium. It is isotonic in animal tissue.

Heart Rate or Pulseheartbeats/minuteDefinition of TermsSystoleperiod when the heart , specifically the LEFT VENTRICLE, is contracting.

Diastoleperiod of relaxation and dilatation (expansion)Frog Heart vs. Human Heart

CriteriaFROGHUMANChamber3 chambers 2 atria1 ventricle4 chambers2 atria2 ventriclesHeart RateSlowerFasterVentricleNot separatedFully separatedPresence of interventricular septumAorta2 arches1 archBloodMixed bloodOxygenated and deoxygenated blood does not mix SizeSmallerLargerRate of HeartbeatPHYSIOLOGY OF THE CIRCULATORY SYSTEMProcedureExpose the heart of a pithed frog by incising midline of thorax and abdomen.Pinch the pericardium with a pair of forceps. Lift it carefully.Keep the heart moist by dropping Amphibian Ringers solution every 15 seconds. DO NOT expose the heart to air currents nor flood with Ringers.Take 3 measurements of the frog heartbeat/minute and compute for the mean.Do the same procedure in number 4 with your partner using a stethoscope. ResultsTrial 1Trial 2Trial 3MEANFrog73727072Human867770781.1 Effect of TemperatureMaterials

Cold and Warm Ringers SolutionEffect of TemperatureProcedureSubject the heart to cold Ringers solution and take the average 3 heartbeat measurements.Normalize heart by applying Ringers at room temperature for two minutes.After it has normalized, apply warm Ringers and take average of 3 heartbeat measurements.ResultsTrial 1Trial 2Trial 3MEANCOLD63656464WARM56595857.67DISCUSSIONTemperature and Heart rate is in DIRECT PROPORTION with each other.

An increased body temperature increases the permeability of the cardiac muscle membrane to ions, resulting in acceleration of self-excitation of the cardiac muscles.1.2 Effect of ActivityProcedureTake average pulse of your partner under the ff. conditions:Sitting quietlyAfter standing at attention for 2 minutesAfter doing jumping jacks for two minutesResultsTrial 1Trial 2Trial 3MEANSitting771108089Standing12213091115Jumping Jacks1551721491591.3 Effect of pHProcedurePlace a drop of 1.0% acetic acid on the heart of a frog and count number of beats/minute.Was off acid with Ringers and count the beats again.Average 3 heartbeat measurements.ResultsTrial 1Trial 2Trial 3MEANAcidic69512649Normal74737072DISCUSSIONpH measurement and heartbeat measurement is in DIRECT proportion with each other.

The normal pH of blood in which the heart is functioning normally is 7.35 to 7.41, which is slightly alkaline. When the heart plasma rises to an acidic pH of more than 7.35, it gradually erodes the smooth muscles of the inner walls of the arteries and veins, as well as the hearts. This weakens the structure of the heart, arteries, and veins, and consequently, their efficiency and function.1.4 Effect of Selected IonsMaterials

0.6% Sodium chloride0.15% Potassium chloride0.012% Calcium chlorideEffect of Selected IonsProcedureWith intense caution, lift the frogs heart well above surrounding vessels. Sever attached vessels (truncus arteriosus and caval veins)Drop the excised heart into the 100 mL beaker of Ringers and cleanse it.Once clean, transfer to another beaker of fresh Ringers and let heartbeat stabilize.

4. Pour 30 mL of each of the ff. solutions given (NaCl, KCl, CaCl2)5. Transfer the heart to the beaker of sodium chloride. Count heartbeat/minute. Return to Ringers to normalize. Repeat thrice and average rate measurement. Do the same with the two solutions.ResultsTrial 1Trial 2Trial 3MEANNaCl86969191CaCl280746472.67KCl80696170DISCUSSIONIn increasing NaCl and CaCl2 concentration, heart rate INCREASES (Direct proportion)In increasing KCl concentration, heart rate DECREASES (Inverse proportion)

The excess of potassium ions in the extracellular fluids causes heart to DILATE thus, the heart rate slows down with elevating potassium concentration. Excess of sodium and calcium ions elevates cardiac rhythm and heart rate.Blood ClottingPHYSIOLOGY OF THE CIRCULATORY SYSTEMIntroductionBlood clotting is vital in the prevention of excessive bleeding once a blood vessel is injured. Platelets and proteins in the plasma stop the bleeding by forming a clot over the injury.HaemostasisHaemostasis or clot formation arrests bleeding when blood vessels are damaged.ProcedureObtain a blood sample from a volunteers left index finger using a capillary tube.Once the tube is filled, keep it warm by holding it in the palm of your hand.After 2 minutes, break 5 mm off the tip of the tube. Note any dried strand of blood that will appear.If no strand appears, keep the tube warm again and break off another piece after 30-second interval.ResultA successful clotting time was achieved in 3 minutes.Why is it necessary to keep the capillary tube warm?In order for the blood to clot faster.DISCUSSIONMajor Steps in Haemostasis

VasoconstrictionPlatelet Plug FormationBlood CoagulationVasoconstrictionThis is the immediate reflex that occurs when a vessel is damaged. This is induced by the release of serotonin, a potent vasodilator, by the platelets due to their adhesion to collagen fibres. Vasoconstriction decreases blood flow and pressure.Platelet Plug FormationOccurs due to adhesion of platelets to collagen fibres, leading to release of ADP and PAF (platelet-activating factor). These chemicals attract more platelets, initiating pseudopod formation that will create a temporary plug. This process is a positive feedback.Blood CoagulationExposed collagen initiates this series of reactions (known as coagulation cascade). Clotting factors released activate prothrombin to become thrombin. Thrombin then activates fibrinogen to become fibrin. Fibrin protein fibre mesh stabilizes platelet plug. Red blood cells adhere to this net, forming the clot.Factors Affecting Blood Clotting ProcessPresence / Absence of Clotting FactorsPlatelet amountTemperatureTemperatureRate of Blood FlowMedications and other substancesSources