33 Questions
What is the function of the atria in the heart?
Collect blood and push it into lower chambers
Where is the heart located in the body?
Between the lungs in the mediastinum
Which structure separates the heart from other structures?
Pericardium
What is the role of the pulmonary vein?
Carry oxygenated blood
Which layer of the heart is most superficial?
Epicardium
What are auricles in relation to the heart?
Thin-walled structures that can hold blood and empty into atria
What happens at 0mV in terms of ion channels during typical repolarization?
Ca++ channels close and K+ channels open
What prevents premature contractions in the cardiac cycle?
Long refractory period
Which ion binds to troponin to allow the myosin and actin cross bridge?
Ca++
If the AV node were to fire at 75 times per minute, what would be an expected outcome?
Arrhythmia
What is the purpose of an electrocardiogram (ECG or EKG)?
To record electrical signals of the heart
What is the role of the P wave in the cardiac cycle?
Depolarization of the atria
Which condition is an interruption in the normal conduction pathway of the heart?
Heart block
What is the primary function of an artificial pacemaker?
To deliver electrical impulses for heart contractions
During which phase of the cardiac cycle does blood flow into the atria and through into the ventricles?
Atrial diastole
What is the main purpose of the isovolumic ventricular relaxation phase in the cardiac cycle?
To close the semilunar valves
How is stroke volume defined in relation to the cardiac cycle?
Amount of blood pushed out by ventricles
Which heart sound is caused by the closing of atrioventricular valves?
S1
What is the percentage range for normal ejection fraction?
50% - 70%
What controls the nervous regulation of heart rate from the medulla oblongata?
Vagal stimulation
What does sympathetic stimulation release that shortens the repolarization period?
Norepinephrine
What causes an increase in parasympathetic stimulation according to the baroreceptor reflex?
Increased stretch
Which factor can lead to a decrease in heart rate?
Hypoxia
Which structure divides the heart into chambers and are physical extensions of the myocardium?
Septum
What is the main function of endothelins released by the endothelium?
Regulate growth patterns of cardiac muscle cells
Which valves separate the atria from ventricles in the heart?
Atrioventricular valves
What is the main function of the moderator band in the right ventricle?
Help regulate cardiac conduction
Where does the left atrium receive blood from?
Pulmonary veins
Which valves ensure unidirectional blood flow in the heart?
Semilunar valves
What happens during a heart murmur caused by valve disorders?
Abnormal heart sounds during auscultation
Which of the following is responsible for setting the normal cardiac rhythm and known as the pacemaker?
Sinoatrial (SA) node
Plateau phase in cardiac muscle cells occurs at which membrane potential?
+30mV
Desmosomes in cardiac muscle cells serve to prevent what from happening?
Rupture or tearing apart of cells
Test your knowledge on the key components and functions of the cardiac conduction system, including the roles of calcium ions, action potentials, and refractory periods. Understand the sequence of events from the SA node to the bundle branches.
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