Heart homework
Place the following parts of the cardiac conduction system in the order in which they transmit the action potential. 1) atrioventricular (AV) bundle 2) Purkinje fibers 3) sinoatrial (SA) node 4) right and left bundle branches 5) contractile cells of cardiac muscle tissue 6) atrioventricular (AV) node
3, 6, 1, 4, 2, 5
Which wave on the electrocardiogram (ECG) represents ventricular depolarization?
QRS wave
The main pacemaker of the heart is the __________.
SA node
Which of the following happens immediately after the P wave?
The atria contract.
Determine the impact if the connection between the sinoatrial (SA) node and the atrioventricular (AV) node becomes blocked.
The ventricles will beat more slowly.
What activity is occurring in the heart during the Q-T interval on an electrocardiogram (ECG)?
The ventricular cells are undergoing action potentials.
What vessel delivers oxygenated blood to systemic capillaries for gas exchange?
aorta
Where should the left ventricle send blood?
aorta
What is NOT part of the cardiac conduction system? atrioventricular (AV) valve sinoatrial (SA) node atrioventricular (AV) bundle atrioventricular (AV) node
atrioventricular (AV) valve
what is a good description of cardiac muscle fibers?
branched, uninucleate cells with intercalated discs
The electrical impulse is __________ as it passes through the AV node, because the atria need to contract __________ ventricles.
delayed, before
The right side of the heart receives:
deoxygenated blood from the systemic circuit.
High pressured blood in the ventricles:
forces the semilunar valves open.
Which structure is a remnant of the foramen ovale?
fossa ovalis
Coronary circulation involves the delivery of oxygenated blood to the:
heart
What characteristic differentiates cardiac muscle cells from skeletal muscle cells?
intercalated discs
Which structure separates the right and left ventricles?
interventricular septum
Ventricular systole begins during the __________ phase of the cardiac cycle.
isovolumetric contraction
Blood returning from the lungs enters the __________.
left atrium
If a drop of blood is located in aorta and needs to go to the infero-anterior apex of the heart, what vessel will it pass through next?
left coronary artery
The cardiac chamber with the thickest wall is the __________.
left ventricle
The pulmonary circuit involves blood flow from the heart to and from the:
lungs
What muscles, present in the ventricles, anchor by tendon-like chords called chordae tendineae?
papillary muscles
The aortic valve closes when __________.
pressure in the left ventricle falls below aortic pressure
The AV valves close when __________.
pressure in the ventricles increases
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
What vessel(s) deliver oxygenated blood to the left atrium?
pulmonary vein
Which of the following does NOT return blood to the right atrium of the heart?
pulmonary vein
Which of the following vessels carries oxygenated blood?
pulmonary vein
What normally serves as the pacemaker of the entire heart?
sinoatrial (SA) node
The right and left atria depolarize and contract following the arrival of the action potential from the:
sinoatrial (SA) node.
What causes striations in the cardiac muscle cells?
the overlapping of the actin and myosin proteins of the myofilaments
Blood in the right atrium should travel next past the:
tricuspid valve and into the right ventricle.
true or false The left ventricle has greater muscle mass than the right ventricle since it pumps against greater resistance.
true
Both the left and right atria receive blood from:
veins
The chambers that have just emptied when the second heart sound is heard are the __________.
ventricles
The T wave of an ECG corresponds to __________.
ventricular repolarization
