Chapter 14/15 tutorial
Which of the following is the effect of the parasympathetic nervous system when blood pressure is too high? A decrease heart rate B decrease force of contraction of the heart C reduce blood volume D induce relaxation of arteriolar smooth muscle
A
Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?
AV node
Increased pressure in the ventricles would close what valve(s)?
AV valves only
An intracellular recording of electrical activity in either a contractile cell or autorhythmic cell is known as a(n)
Action potential
_______________is an electrode placement technique that uses three leads in order to record an electrocardiogram.
Einthoven's triangle
An extracellular recording of electrical activity of both autorhythmic and contractile cells of the heart is known as a(n)
Electrocardiogram
A two electrode part constitutes a ________ which records the electrical activity of the heart
Lead
Which of the following is correct about the filling of the ventricles?
Most blood flows passively into the ventricles through open AV valves.
Atrial depolarization__________
P wave
Contraction of the atria results from which wave of depolarization on the ECG tracing?
P wave
COnduction through the atrioventrucluar (AV) node_______
PR segment
Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.
Pressure in the atria would be greater than the pressure in the ventricles.
Conduction through the atrioventricular (AV) bundle_________
Q wave
Ventricular depolarization_____________
QRS complex
Which portion of a normal ECG represents ventricular depolarization?
QRS complex
Total time it takes for the ventricular muscle to depolarize and repolarize__________
QT interval
Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?
SA node
The ventricles are in their depolarized state_________
ST segment
Ventricular repolarization________
T wave
how are arteriolar smooth muscle reglated
alpah receptros which bind to norepinephrine and epinephrine
A decrease in blood pressure at the arterial baroreceptors would result in which of the following
an increase in heart contractility
Stimulation of the adrenal medulla would result in which of the following?
an increase in heart rate and contractility
Which of the following events is NOT represented on an ECG?
atrial repolarization
how is the SA node reulgated
bete receptros that bind to epinephrine and norepinephrine and muscarinic receptors which bind to acetylcholine
Which of the following cardiovascular control factors contribute to changes in blood pressure?
blood vessel diameter, heart rate, force of cardiac contraction
Where are the sensors for the arterial baroreceptor reflex located?
carotid sinus and aortic arch
Which of the following would cause vasodilation of arterioles?
decreased activity of the sympathetic nervous system
How would a decrease in blood volume affect both stroke volume and cardiac output?
decreased stroke volume and no change in cardiac output
What does the ECG wave tracing represent?
electrical activity in the heart
Which of the following would increase heart rate?
epinephrine and norepinephrine
What causes the aortic semilunar valve to close?
greater pressure in the aorta than in the left ventricle
If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?
increased PNS activity and decreased SNS activity
How would an increase in the sympathetic nervous system increase stroke volume?
increased contractility
By what mechanism would an increase in venous return increase stroke volume?
increased end diastolic volume
Which of the following would increase cardiac output to the greatest extent?
increased heart rate and increased stroke volume
Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.
isovolumetric contraction, ventricular ejection, isovolumetric relaxation
what is the equation for blood pressure
mean arterial pressure is proportional to cardiac output times Total peripheral resistance
Which of the following neurotransmitters will play a role in the regulation of blood pressure by creating a change in cardiovascular function?
norepinephrine, acetylcholine, epinephrine
how is the ventricular myocardium regulatided
the Beta receptors bind to epinephrine and norepinephrine
Part complete Which of the following statements best describes the electrical events recorded by an ECG?
the sum of the electrical activity of all cells in the heart
What does the QRS complex represent in the ECG wave tracing?
ventricular depolarization
Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.
ventricular diastole
