Ch. 17
Calculate the end-systolic volume (ESV) if the end-diastolic volume (EDV) in a resting heart is 110 ml and the stoke volume (SV) is 70 ml.
40 ml EDV-ESV=SV
How much blood is pumped from each ventricle during the ventricular ejection phase?
70 ml
Which chemical messenger decreases heart rate?
Acetylcholine
Which hormone decreases cardiac output by decreasing blood volume and preload?
Atrial natriuretic peptide
What largely determines preload?
End-diastolic volume (EDV)
A damaged atrioventricular (AV) bundle or AV node will primarily affect the length of the _________
P-R interval
During what part of the action potential will calcium ions enter the contractile cell?
Plateau phase
What is the function of the valves in the heart?
Prevent backflow of blood through the heart
Which vessel is guarded by a semilunar valve at its base?
Pulmonary trunk
Which of the following vessels carries oxygenated blood?
Pulmonary vein
What vessels deliver oxygenated blood to the left atrium?
Pulmonary veins
Which EKG finding can be used to measure heart rate?
R-R interval
What valve presents the backflow of blood from the right ventricle into the right atrium?
Right atrioventricular valve (tricuspid valve)
What normally serves as the pacemaker of the entire heart?
Sinoatrial (SA) node
What two values are needed to calculate cardiac output (CO) for a ventricle?
Stroke volume (SV) and heart rate (HR)
The P wave on an ECG represents the depolarization of cells in the ___________
atria
Autorhythmicity in the heart is the responsibility of _________
cardiac pacemaker cells
Inotropic agents affect _________
contractility
The right side of the heart receives _______________
deoxygenated blood from the systemic circuit
The visceral pericardium is the same as the _________
epicardium
High-pressured blood in the ventricles ___________
forces the semilunar valves to open
The degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called
preload
The right and left atria depolarize and contract following the arrival of the action potential from the __________
sinoatrial node SA
Blood in the right atrium should travel next pass the __________
tricuspid valve and into the right ventricle
Both the left and right atria receive blood from _________
veins
