Cardiac output cannot increase indefinitely because (a) available filling time becomes shorter as the heart rate increases. (b) the cardiac center adjusts the heart rate. (c) the rate of spontaneous depolarization decreases. (d) the ion concentrations surrounding pacemaker plasma membranes decrease.

Using information provided in the text, calculate the power generated by the right ventricle during (a) restful state; blood flow 5 liter/min, and (b) intense activity; blood flow 25 liter/min.

Your grandfather was told that his SA node (pacemaker) had stopped functioning. Explain how his heart is still beating at a rate of 40-50 times per minute. Are the atria still being stimulated to contract, and what area of the heart is stimulating them?

How does the cardiac contractile refractory period differ from a typical skeletal muscle refractory period?

What condition(s) does increasing the diameter of the left flow tube simulate in the human heart (A) increasing afterload (B) increasing preload (C) increasing viscosity of the blood (D) increasing the contractility of the ventricles

1) Where the action potential is generated (i.e. atria or ventricles) 2) What actions are occurring during this process (i.e. contraction and ion flow) 3) When relaxation occurs

How would you explain the flow of electrical activity through the heart to a 5-year-old?

Roberto is a 78-year-old male who has recently been diagnosed with Class III Congestive Heart Failure (CHF). His physician told him that his left ventricle has become stiff and cannot relax. Although there is no current treatment that can “fix” Roberto’s condition, he is prescribed two medications: an ACE inhibitor and beta blockers.Briefly describe how beta-blockers will influence Roberto’s heart function, specifically the physiology of the ventricles.

4) A) Calculate the Systolic Pressure of a 65 years old man if the diastolic blood pressure is 90 mmHg and stroke volume of 70 ml/beat. Total Peripheral Resistance is 19mmHg.min/L. Assume person is healthy and has a normal heart rate. B) Calculate Left ventricular end-diastolic volume (LVEDV) when the mean ejection fraction is 80 % ?

An increase in mean blood pressure may be due to? a) an increase in heart rate b) an increase in peripheral resistance c) an increase in stroke volume