Chapter 17: function of the heart
Excess Vagal stimulation to the SA node is most likely to cause
Bradycardia
Which term refers to a heart rate less than 60 beats/min
Bradycardia
Ventricular systole refers to
Contraction of the ventricular myocardium
Which of the following is the most likely consequence of
A very rapid heart rate
Which of the following I️s most likely to increase stoke volume
A(+) inotropic drug
A patient in heart failure is given a drug that is classified as a beta1- adrenergic agonist. The drug
Activates the beta1-adernergic receptors and causes a + inotropic effect
Which of the following is most likely to increase ejection fraction
Activation of beta1-adrenergic receptors
Contains 70mL
An average stroke volume
Refers to a positive inotropic effect
An increased myocardial contractile force
Decreased blood flow through the coronary arteries is most likely to cause
Angina pectoris
Systole and diastole describe the function of the
Myocardium
Which of the following is descriptive of the vagus nerve
Parasympathetic
Which of the following most accurately describes the vagus nerve
Parasympathetic
Which of the following is least likely to be used in the treatment left ventricular failure pulmonary edema
Peripheral vasoconstrictor such as norepinephrine (levophed)
Starlings law of the heart relates force of myocardial contraction with
Preload
Which of the following is the same as end-diastolic volume
Preload
Most likely consequence of acute left ventricular failure
Pulmonary edema
Atropine is a muscarinic antagonist and is therefore used to
Relieve bradycardia
Most of the symptoms of acute left sided heart failure are
Respiratory in nature (dyspnea, orthopnea)
Jugular vein distention is most associated with
Right sided heart failure
An elevation in pulmonary artery pressure is most likely to cause
Right ventricular hypertrophy
During atrial systole, the
Ventricles are relaxed
Digoxin, a drug used in the treatment of heart failure, increases contractile force and is therefore called a
+ inotropic agent
Which of the following drugs is sympathomimetic
Beta1-adrenergic agonist
Most likely to relieve an anxiety-induced tachycardia
Beta1-adrenergic blocker
Term for the sequence of events that accurately during one heart beat
Cardiac cycle
Heart rate and stroke volume determine
Cardiac output
Milliliters per minute describes
Cardiac output
Milliliters/beat,beats/min defines
Cardiac output
Which term refers to the amount of blood pumped by the heart in 1 minute
Cardiac output
Which of the following is correct about cardiac output
Cardiac output is determined by heart rate and stroke volume
Sympathetic nerve stimulation of the myocardium
Causes a(+) inotropic effect
An ejection fraction of 30% is
Characteristic of a failing heart
Venodilation
Decreases preload
Example of forward failure
Diminished renal blood flow stimulates the kidney to decrease urinary output and retain Na+ and water
Which of the following does not happen to a ventricle
Discharge of the Vagal nerve
The amount of blood in the ventricle at the end of its resting phase is
End diastolic volume EDV The amount of blood in the ventricle at the end of its resting phase Preload
Which of the following responsible for the starling effect
End-diastolic volume (EDV) or preload
Furosemide (lasix) a potent diuretic. Is administered in a cuter ventricular failure to
Excrete excess water and relieve the edema
Under what condition is end diastolic volume EDV most likely to increase while ejection fraction decreases
Heart failure
Vagal stimulation to the heart causes
Heart rate to slow
Vagal stimulation on the heart
Increases The amount of blood that flows into the heart from the vena cava
A stenotic aortic valve
Increases after load, thereby increasing the work of the left ventricle
A drug that blocks the vagus nerve
Increases heart rate
Atropine, a muscarinic blocker
Increases heart rate
Sympathetic stimulation to the heart
Increases heart rate
An increased preload
Increases stroke volume
Increased after load (hypertension)
Increases the work of the heart
Increased return of blood to the heart stretches the heart muscle thereby
Increasing stoke volume
Increased return of the blood to the heart stretches the muscle, thereby
Increasing stoke volume
Cardiac output
Is determined by heart rate and stroke volume
Which of the following is least related to bradycardia
More than 60 beats per min
A drug causes a + inotropic effect, a - dromotropic effect, and a - chronnotropic effect, what drug response would you expect to observe
Slow heart rate
Activation of the muscarinic receptors by acetylcholine
Slows heart rate
An increase in venous return causes an increase in cardiac output, this is accomplished by
Starling law of the heart
A change in preload causes a change in myocardial contractile force, this response is known as ,,
Starling law of the heart ,,
What is the term that refers to increase in stoke volume in response to the stretching of the heart
Starlings law of the heart
Cardiac output is determined by the heart rate and
Stroke volume
What term refers to the amount of blood pumped by the ventricle in one beat
Stroke volume
Which of the following is descriptive of a drug that causes a + inotropic effect, a + dromotropic effect and a + chronic effect
Sympathomimetic
What happens during the ventricular diastole
The ventricles are filling with blood
Least likely to increase cardiac output
Vagal discharge
Least related to tachydysrhymthias ,,
Vagal discharge ,,
