During the period of isovolumic contraction: A. the AV-valves are open and the aortic & pulmonary arterial valves are closed. B. all valves are open. C. all valves are closed. D. the AV-valves are closed and the aortic & pulmonary arterial valves are open. E. None of the above is correct.

Which of the following statements is correct regarding the cardiac conduction system: A the AV node is the natural pacemaker B C D internodal fibers conduct signals to the atrial myocardial cells to contract the R/L bundle branches are located in the interatrial septum the bundle of His sends a signal to the papillary muscles to contract

Label the following parts:

during isometric ventricular contraction: a. the entry and exit valves of the ventricle are closedb. pressure in the aorta arisesc. pressure in the atria fallsd. the rate of rise in pressure is greater in the right than in the left ventriclee. volume of the ventricle increases

When does isovolumetric relaxation occur?   A immediately after atrial contraction   B at the end of diastole   C immediately after the QRS wave on the ECG   D immediately after ventricular contraction   E ALL OF THE ABOVE

In a healthy heart during exercise, cardiac output increases as heart rate increases up to about 120bpm, as stroke volume remains constant (CO = HR x SV). As heart rate goes further up, the cardiac output remains stable, and above 160bm it decreases. Why does it decrease?    A. shorter filling time decreases stroke volume  B. venous return decreases  C. valves cannot open and close fast enough  D. contractile power of heart muscle cells increases

In resting state: For a heart that would have a left ventricle of 130 mL of end diastolic volume (EDV) and 60 mL of end systolic volume (ESV) and a heart rate 60 bpm. A. Calculate the output your pump should provide to the aortic arch. (in units of L/min) B. In moderate activity state: If the heart rate is expected to increase by 15% Calculate the output your pump should provide to the aortic arch hibernation levels so they can go back to sleep. A mitochondria-rich tissue called "brown fat" is responsible for this heat-generation.

With atherosclerosis, what happens to resistance and flow? O 1) resistance decreases, flow increases 2) resistance and flow decrease 3) resistance and flow increase O 4) resistance increases, flow decreases

Papillary muscles:     options:   assist the opening of closure of the semi-lunar valves.   are a type of smooth muscle.   upon contraction, pull on the chordae tendinae holding the AV valve leaflets closed.   are smooth muscle extensions of the walls of the ventricles.   prevent the AV valve leaflets bulging too far into the aorta during ventricular systole.

40. The period of ejection:   A. begins with closure of the AV-valves and ends with opening of the AV-valves B. begins with opening of the aortic valve and ends with closure of the aortic valve C. begins with the P-wave and ends with the QRS-complex D. begins with the QRS-complex and ends with the T-wave