Questions and Answers
The semilunar valves remain open throughout the __________ phase of the cardiac cycle.
late ventricular systole
The atria remain in diastole throughout both the __________ phases of the cardiac cycle.
ventricular systole and early to mid ventricular diastole
Positive inotropes allow the heart to pump __________ blood with fewer heartbeats. They do this by __________ the end-systolic volume (ESV).
more; decreasing
An individual with high blood pressure (hypertension) is expected to benefit from the administration of __________ inotropic drugs that __________ the heart's workload.
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The expected effect of the drug Digoxin is to __________ ventricular contraction and __________ stroke volume.
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A first-degree block is caused by __________.
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What is the rate of ventricular conduction best determined by on an ECG?
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An ECG tracing from someone with a third-degree AV block is best described as a tracing with a __________.
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The semilunar valves close during __________.
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The atrioventricular valves open during __________.
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When the pressure in the ventricles becomes lower than the pressure in the atria, __________.
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In the heart, an action potential originates in the __________.
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Which of the following is the correct sequential path of an action potential in the heart?
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Action potentials pass slowly through the atrioventricular node.
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Heart sound __________ is thought to result from the transition from expansion of the empty ventricles to their sudden filling with blood.
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If a person's heart is pumping 5000 mL of blood in one minute and the heart rate is 50 beats per minute, what is the cardiac output?
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The difference between the maximum and resting cardiac output is called __________.
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The Frank-Starling law of the heart states that an additional stretch of the myocardium produces a significant increase in __________ on the next beat.
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What is the broad flat superior top portion of the heart called?
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What is the double layered sac that surrounds the heart called?
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What are the thick inferior chambers of the heart that pump blood into the arteries called?
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The passage of blood from the atria to the ventricles is regulated by which valves?
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What is the ability to rhythmically depolarize without outside stimulation called?
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Which term refers to relaxation of the heart?
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As a heart chamber contracts, what happens to the pressure of the fluid within it?
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Study Notes
Cardiac Cycle Phases
- Late ventricular systole features open semilunar valves during contraction of the ventricles.
- Atria remain in diastole during ventricular systole and early to mid ventricular diastole.
Inotropic Agents
- Positive inotropes enhance heart function by allowing more blood to be pumped with fewer beats, decreasing end-systolic volume.
- Negative inotropic drugs are beneficial for individuals with hypertension by decreasing the workload on the heart.
Cardiac Output and Stroke Volume
- Digoxin strengthens ventricular contractions and increases stroke volume.
- Cardiac output can be calculated by multiplying heart rate by stroke volume; for example, 5000 mL/min with a heart rate of 50 bpm may not yield standard answers provided.
Electrical Conduction System
- A first-degree AV block occurs due to a delay of action potentials between the SA and AV nodes.
- The ventricular conduction rate is determined by the number of QRS complexes in a specific time frame.
ECG Patterns
- A third-degree AV block is characterized by a 2:1 ratio of P waves to QRS complexes.
Heart Valves Functionality
- Semilunar valves close during ventricular diastole, while atrioventricular valves open during this phase.
- When ventricular pressure drops below atrial pressure, the atrioventricular valves open.
Pacemaker Activity
- The sinoatrial node is the primary source of action potential in the heart.
- The correct sequence of action potential propagation is sinoatrial node, atrioventricular node, atrioventricular bundle, bundle branches, and Purkinje fibers.
Conduction System Characteristics
- Action potentials move slowly through the atrioventricular node, allowing for proper timing of cardiac contractions.
Heart Sounds
- The S3 heart sound is associated with ventricular filling, indicating the transition from empty to filled ventricles.
Cardiac Reserve
- Cardiac reserve represents the difference between maximum and resting cardiac outputs.
Frank-Starling Law
- The Frank-Starling law states that increased myocardial stretch leads to greater contraction force in the subsequent heartbeat.
Heart Anatomy
- The base is the broad, flat superior top portion of the heart.
- The pericardium is the double-layered sac that encases the heart, while the ventricles are the thick chambers responsible for pumping blood to the arteries.
- Blood flow from the atria to ventricles is regulated by atrioventricular valves.
Cardiac Physiology Terms
- Autorhythmicity refers to the heart's ability to generate rhythmic depolarizations independently.
- Diastole is the term denoting relaxation of the heart, opposite of systole.
Hemodynamic Changes
- Pressure within a contracting heart chamber increases as the chamber contracts.
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Description
Prepare for your Anatomy & Physiology 2 exam with this Chapter 19 test review quiz. The questions focus on the cardiac cycle phases, including systole and diastole. Use these flashcards to reinforce your understanding of cardiovascular concepts.
