moodle quizzes exam 3 Flashcards
which vessels supply cardiac cells with oxygen and nutrients or help them getting rid of their wastes? (2)
coronary arteries
coronary veins
The four valves of the heart make a sound when they ______. The sounds made by the valves can be heard as a lup-dup allowing us to listen to our heart. Sometimes, when using a stethoscope to listen to the heart, a muffling sound can be heard on top of the normal lup-dub. This happens in people that have a _______ _______ . This condition may arise from a valve ___________
. Since the valve is not perfectly ________
during heart contraction, some blood flows back into the cavity it came from.
close
heart murmur
malfunction
closed
True or False.
An ECG is a graphic representation of the heart’s contractions.
false
The ECG represents a tracing of ELECTRICAL SIGNALS happening in the heart.
Select all the correct statements about the cardiac muscle.
A.
Contractile cells have gap junctions between them, they make it possible for the action potential to travel from one cell to the next to have a simultaneous contraction.
B.
Most cells of the cardiac muscle tissue are contractile cells, while the remaining are conducting cells.
C.
Intercalated discs are regions of the cardiac muscle where action potentials are initiated.
D.
The conduction cells of the heart are responsible to initiate and propagate action potentials.
E.
The heart determines its own beat, nothing can change that.
A.
Contractile cells have gap junctions between them, they make it possible for the action potential to travel from one cell to the next to have a simultaneous contraction.
B.
Most cells of the cardiac muscle tissue are contractile cells, while the remaining are conducting cells.
D.
The conduction cells of the heart are responsible to initiate and propagate action potentials.
Order the structures responsible to carry the action potential through the heart (4)
SAAP
→ Sinoatrial node,
→ Atrioventricular node,
→ Atrioventricular bundle,
→ Purkinje fibers
Order the events of the cardiac cycle. Assume that the cycle starts with the conduction system resting.
(8 steps)
- → The cardiac conduction system is resting.
- → The sinoatrial node initiate the action potential.,
- → The action potential spread across the atria, then they contract.,
- → The action potential reaches the atrioventricular node which pauses the signal shortly.,
- → The atria finished their contraction while the AV node paused the signal.,
- → The action potential travels down to the heart’s apex using the atrioventricular bundle.,
- → At the heart’s apex, the action potential spread upwards in the ventricles using Purkinje fibers.,
- → The ventricles contract.
Match each deflection of an ECG with the correct event.
QRS
T wave
P wave
QRS: depolarization of the ventricles
P wave: depolarization of the atria
T wave: repolarization of the ventricles
What other name can be given to an atrial or ventricular contraction?
Systole
True or False.
Your heart rate corresponds to how many cardiac cycle your heart completes in a minute.
true
True or False.
A systole is always preceded by the depolarization of the cells about the contract.
explain
True
A systole happens when the contractile cells of the atria or ventricles contract. In order to do so, they need to be told to contract; this is done with an action potential. Thus, the action potential must spread before the systole occurs.
Select all the statements that are correct about the heart rate.
A.
A person suffering from tachycardia has a heart rate extremely slow.
B.
Fibrillation is a rhythm disorder that can be seen on both the atria and ventricles.
C.
The sinoatrial node controls the basic heart rate. However, it can be changed by hormones or action potentials.
D.
A defibrillator is used to impose a pace to the sinoatrial node.
B and C
Fibrillation is a rhythm disorder that can be seen on both the atria and ventricles.
The sinoatrial node controls the basic heart rate. However, it can be changed by hormones or action potentials.
