CH QUIZ 20 Heart
Left ventricular contraction propels blood through which valve?
aortic valve
The atrioventricular valves open during...
atrial systole.
The sequence of travel by an action potential through the heart is...
atrioventricular bundle, atrioventricular node, sinoatrial node, bundle branches, Purkinje fibers.
When blood pressure increases
baroreceptors detect the change in the carotid arteries.
In mitral valve prolapse, the mitral valve
bulges into the left atrium during ventricular contraction.
A rise in the extracellular concentration of __________ produces greater force of cardiac contraction because of more of these ions move into the sarcoplasm during action potential generation.
calcium
Congestive heart failure (CHF) of the right ventricle
can cause systemic edema.
mean atrial pressure
cardiac output times peripheral resistance.
The blood vessels that supply nutrients and oxygen only to the heart muscle make up the specific type of circulation called _______________ circulation.
cornary
_____________ increase(s) stroke volume.
Increased venous return
When blood is flowing out of the left ventricle the bicuspid valve is __________ and the aortic semilunar valve is __________.
closed; open
The chambers of the human heart are the right and left ______________ and __________.
ventricles ; atrium
The atrioventricular valves open during
ventricular diastole.
This figure shows the principal coronary blood vessels. Which one is the left coronary artery (LCA)?
3
The heart is said to be __________ because it stimulates itself to contract at regular intervals.
Autorhythmic
The figure illustrates the cardiac action potential. What does "D" represent?
FINAL
Atrial contraction accounts for most of the ventricular filling.
False
Chemoreceptors in the hypothalamus monitor blood carbon dioxide and pH.
False
Heart rate and stroke volume decrease under decreased parasympathetic stimulation.
False
Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal.
False
Isovolumetric contraction occurs during the _________ of the electrocardiogram.
R wave
Oxygen-poor blood enters which chamber of the heart?
Right atrium
In the heart, an action potential originates in the
SA NODE
T wave (ventricular repolarization)
T wave (ventricular repolarization)
Increased sympathetic stimulation causes increased heart rate and stroke volume.
True
During this phase, _____ channels remain open and movement of those ions into the cell counter acts the potential change produced by the movement of potassium ions
all
Excess potassium ions in cardiac tissue will cause the heart rate and stroke volume to __________.
decrease
Most of the ventricle filling occurs
during atrial diastole.
An __________ focus is any part of the heart other than the SA node that generates a heartbeat.
ectopic
The pericardium consists of a tough, fibrous connective tissue outer layer called the __________ pericardium.
fibrous
The __________ is a low-pitched sound caused by vibration of the atrioventricular valves and surrounding fluid as the valves close at the beginning of ventricular systole.
first heart sound
The __________ is a low-pitched sound caused by vibration of the atrioventricular valves and surrounding fluid as the valves close at the beginning of ventricular systole.
first sound
Baroreceptors are located in the
in the aorta and carotid arteries.
Which of the following will not increase the heart rate?
increased blood pressure
The steps of the cardiac cycle in sequence are...
isovolumic contraction, ejection, isovolumic relaxation, passive ventricular filling, active ventricular filling.
Mitral valve stenosis causes blood to leak back into the ___________ when the ventricles contract.
left atrium
Mitral valve stenosis causes blood to leak back into the ___________ when ventricles contract.
left atrium
The __________ has four relatively uniform openings that receive blood from the four pulmonary veins from the lungs.
left atrium
Oxygenated blood flows from the __________ to the __________ before being pumped into the systemic circulation
left atrium, left ventricle
Mitral valve prolapse (MVP) generates a murmur associated with the _____ heart sound that occurs when the ____.
lubb (S1); ventricles contract
Chemoreceptors are also located in the...
medulla oblongata.
Cardiac output is equal to heart rate times ____ _______.
stroke volume
Oxygen leaves the blood and carbon dioxide enters the blood in the
systemic capillaries
Afterload is
the arterial pressure that the ventricles must overcome to eject blood.
When the pressure in the ventricles becomes lower than the pressure in the atria...
the atrioventricular valves open.
Ventricular systole causes...
the atrioventricular valves to close, and then the semilunar valves to open.
During __________ all of the valves are closed as pressure builds in the ventricles.
the period of isovolumetric contraction
The atria never need to contract due to passive ventricular filling.
False
The alternate name for the left atrioventricular (AV) valve is called _______________.
bicuspid valve
The three vessels that return deoxynated blood to the RIGHT ATRIUM are called the ________ ___________ and the superior and inferior _________________ ____________.
coronary sinus vena cava
Oxygen-poor blood enters which chamber of the heart?
right atrium
This figure shows action potential of a ventricular cardiocyte. _____________ indicates when sodium channels are fully open.
2
The long plateau in the action potential observed in cardiocytes is probably related with _____________ staying longer in their cytosol.
Ca2+
The figure illustrates the cardiac action potential. What does "B" represent?
EALRY repolarization
An __________ focus is any part of the heart other than the SA node that generates a heartbeat.
Ectopic focus
The beginning of ventricular systole is when blood flowing back toward the relaxed ventricles causes the semilunar valves to close.
False
The resting membrane potential of cardiac muscle cells depends on a low permeability of the plasma membrane to sodium and potassium and a higher permeability to calcium.
False
Match the cardiac cycle event with the correct ventricular activity. AV valves are open Ventricular systole incorrect Semilunar valves are open Ventricular diastole incorrect First heart sound Ventricular systole correct Second heart sound Ventricular diastole correct Third heart sound Ventricular systole incorrect
Match the cardiac cycle event with the correct ventricular activity. AV valves are open Ventricular systole incorrect Semilunar valves are open Ventricular diastole incorrect First heart sound Ventricular systole correct Second heart sound Ventricular diastole correct Third heart sound Ventricular systole incorrect
Match the vessel with the chamber it is associated with: Inferior and superior vena cava Right atrium correct Pulmonary trunk Right ventricle correct Pulmonary veins Left atrium correct Aorta Left ventricle correct
Match the vessel with the chamber it is associated with: Inferior and superior vena cava Right atrium correct Pulmonary trunk Right ventricle correct Pulmonary veins Left atrium correct Aorta Left ventricle correct
P wave (atrial depolarization)
P wave (atrial depolarization)
Which of the following waves of an ECG pattern is/are correctly described?
P wave-depolarization of atria
The generation of action potentials in the SA node results when a spontaneously developing local potential, called the __________ potential, reaches threshold.
Pacemaker
The QRS wave is sometimes called the QRS complex, and it represents the depolarization of the ventricles.
The QRS wave is sometimes called the QRS complex, and it represents the depolarization of the ventricles.
When blood pH increases
blood carbon dioxide levels increase.
Chemoreceptors in the carotid and aortic bodies detect all of the following except
blood pressure
Chemoreceptors in the carotid and aortic bodies detect all of the following except...
blood pressure
In __________ regulation neural and hormonal control mechanisms assist in controlling the cardiac output.
extrinsic
Atrial contraction accounts for most of the ventricular filling.
false
Cardiac muscle has refractory periods, during the relative refractory period, the cell is completely insensitive to further stimulation
false
The only arteries in the body that carry oxygen-poor blood are the coronary arteries.
false
When blood is flowing into the left ventricle the bicuspid valve is __________ and the aortic semilunar valve is __________.
open; closed
The generation of action potentials in the SA node results when a spontaneously developing local potential, called the __________ potential, reaches threshold.
pacemaker
During __________ the AV valves open, and blood flows from the atria into the ventricles.
passive ventricular filling
The right side of the heart pumps blood through vessels to the lungs and back to the left side of the heart through the __________ circulation.
pulmonary
During __________ all of the valves are closed as ventricles begin diastole.
the period of isovolumetric relaxation
The right atrium receives blood directly from
the superior vena cava, inferior vena cava, and coronary sinus.
Action potentials are conducted from the baroreceptors to the brain via...
the vagus and glossopharyngeal nerves.
The action potential from the brain to the heart travels along...
the vagus nerve.
Which of the following is not true for ventricular systole?
the ventricles relax.
Action potentials are carried by the Purkinje fibers from the bundle branches to the ventricular walls.
true
The action potential travels along the interventricular septum to the apex of the heart, where it then spreads superiorly along the ventricular walls.
true
The plateau phase of the action potential in cardiac muscle delays repolarization to the resting membrane potential therefore the refractory period is prolonged
true
The ventricles begin to fill during ventricular diastole.
true
The semilunar valves close during
ventricular diastole.
The semilunar valves close during...
ventricular diastole.
The ventricles begin to fill during ventricular diastole.
True
A reduction in extracellular potassium ions causes the resting membrane potential to become __________; as a consequence, it takes longer for the membrane to depolarize to threshold.
Hyperpolarized
The wall of the __________ is much thicker than any other chamber in the heart which allows for stronger contractions to pump blood through the systemic circulation.
Left Ventricle
Period of isovolumetric contractionVentricular systole correct Period of isovolumetric relaxationVentricular diastole correct Passive ventricular fillingVentricular diastole correct Period of ejectionVentricular systole correct
Period of isovolumetric contractionVentricular systole correct Period of isovolumetric relaxationVentricular diastole correct Passive ventricular fillingVentricular diastole correct Period of ejectionVentricular systole correct
What are the structures included in the heart's conduction system? Check all that apply.
Purkinje fibers Atrioventricular bundle Atrioventricular (AV) node Sinoatrial (SA) node
