An individual presents with cardiac tamponade.  Their heart would be the most efficient in pumping out blood during which of the following?

John is your 68-year old neighbor who was recently told by his doctor that his heart’s main pacemaker stopped working (“They told me it is called an SA node”). He knows you are a nurse, so he came to you to ask why his heart is still beating, but only at a rate of 50 times per minute. Please explain using appropriate physiological and anatomical details.

Consider a person standing up from a supine position. How do each of the following parameters change in the first seconds after standing compared to what they were at rest, before they return to normal set point? Total Peripheral Resistance (TPR) Venous Return End Diastolic Volume (EDV) Stroke Volume Heart Rate Mean Arterial Pressure (MAP) [Choose ] ✓ [Choose ] No change Decrease Increase [Choose ] [Choose ] [Choose ]

What is occurring during ventricular ejection ? The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles . The AV valves are open and the semilunar valves are closed as ventricular pressure is . increasing The AV valves are open and the semilunar valves are closed as blood is leaving the ventricles . The AV and semilunar valves are closed as ventricular pressure is increasing .

isovolumetric contraction isovolumetric relaxation ventricular filling ventricular ejection closed rises S1 drops depolarize S2 The first phase of the cardiac cycle is . This is when a lot of blood is in the atria, which causes atrial pressure to be higher than the ventricles. The atrioventricular valves open, and blood moves from the atria to the ventricles. At the end of this phase, the atria contract to maintain pressure and blood flow into the ventricles. As blood leaves the atria, the pressure in the atria As blood enters the ventricles, the pressure in the ventricles Towards the end of this phase, the pressure in the ventricles will exceed the pressure in the atria. At this point, the heart enters the second phase of the cardiac cycle: At this point, the AV valves shut, and we hear . The atria repolarize and the ventricles (due to the QRS complex of the ECG), causing ventricular contraction. Although contracting, it is not yet moving blood into the arteries. All 4 heart valves…

Which of the following statements best describes the differences in the regulation of cardiac and skeletal muscle contraction?     The amount of contractile force actively generated by muscle cells is increased by stretch in skeletal muscle and decreased by stretch in cardiac muscle.     Cardiac muscle is stimulated by motor neurons and skeletal muscle by neurones from the autonomic nervous system.     Skeletal muscle contractile force is augmented by increasing the firing frequency of action potentials whereas cardiac muscle contractile force is enhanced by noradrenaline increasing calcium influx through ion channels.     Ryanodine receptors in skeletal muscle are opened by a mechanism that requires calcium influx whereas in cardiac muscle membrane depolarisation alone without calcium influx is sufficient to open ryanodine receptors.

As we auscultate the heart it is imperative, we understand what part of the heart we are listening to. Cellular senescence is observed when there is obstruction of the coronary circulation to the muscle tissue of the heart. If the left anterior descending artery (a.k.a. “Widow maker”) is occluded, predict an alternative route of blood flow to the myocardium. Start from the left coronary artery.

Given the role of potassium in myocardial cell action potentials, explain how hyperkalemia can stop the heart. Make sure to explain in terms of ion movements

The following medications are used to treat an exacerbation of congestive heart failure.  Each one of them is actually used to counteract mechanisms the body has naturally set in place in response to a drop in blood pressure and presumed drop in tissue perfusion.  For each medication, explain its affect(s) on A, B, and C.  If you feel it has no effect on a particular parameter, then say "no effect".  Specifically for each:  A)  affect on TPR (total peripheral resistance) and how/why it changes it  B)  affect on cardiac output (contractility, heart rate, stroke volume) and how/why it changes it  C)  blood volume/pressure and how/why it changes it  ACEIs (ACE inhibitors) Beta blockers Digoxin Nitrates (nitroglycerin, isosorbide) Diuretics like Lasix

You have just started a rigorous exercise. Explain two different ways you can increase blood flow to your skeletal muscle (one must reflect upon changes in cardiac output and the other on a change in resistance)