34 Questions
Where is the heart located in the body?
Between the lungs in the mediastinum
What separates the heart from other structures?
Pericardium
How many chambers does a typical heart have?
4 chambers
Which part of the heart pumps blood out to the body or lungs?
Ventricles
What is the role of auricles in the heart?
Pump blood into the atria
Which layer of the heart is the most superficial?
Epicardium
What is the role of Ca++ channels at 0mV in the heart?
Closing to prevent premature contractions
Which part of the heart has the slow Ca++ channels that allow for the plateau phase?
Purkinje fibers
If not for endocrine control, how many times per minute would the AV node fire?
40 - 60
What is the purpose of electrodes placed on the body in relation to the heart's electrical signals?
To record electrical signals of the heart
What is the abbreviation commonly used for Electrocardiogram?
ECG
What is the main purpose of AEDs in relation to cardiac issues?
To correct fibrillations
Which phase of the cardiac cycle involves pumping blood into circulation?
Ventricular systole
What happens during atrial systole in the cardiac cycle?
Atria contract to push blood into the ventricles
What is the role of myoglobin in cardiac muscle metabolism?
Storing oxygen in muscle cells
What represents the amount of blood left in the ventricles after stroke volume is pushed out?
End systolic volume (ESV)
What characterizes the phase of ventricular diastole in the cardiac cycle?
Relaxation with semilunar valves open and atrioventricular valves closed
What is the function of the endothelium in the heart?
Releases strong vasoconstrictors
Which structure divides the heart into chambers and is a physical extension of the myocardium?
Septum
What is the main function of the atrioventricular (AV) node in the heart?
Forces the atrioventricular septum to contract
How does the sinoatrial (SA) node contribute to cardiac function?
Inferior portion of right atrium known as the pacemaker
What is the role of desmosomes in cardiac muscle cells?
Stop cardiac muscle cells from ripping apart
Why do valve disorders primarily occur in the heart?
Due to inflammation
Which type of cell initiates and propagates the action potential through the heart?
Myocardial conducting cells
During which phase do cardiac contractile cells plateau before repolarizing?
+30mV Na+ channels close
Which heart sound is associated with the closing of atrioventricular valves?
S1
What does S2 represent in terms of heart sounds?
Opening of semilunar valves
What term is used when both S3 and S4 heart sounds are present?
S7
What is the formula for calculating Cardiac Output (CO)?
CO = HR * SV
What is the normal range for Cardiac Output (CO) in a healthy individual?
$4 - 8$ L/min
What percentage of blood pumped represents the Ejection Fraction?
$50 - 70$%
What is the target heart rate range used to maintain a high Cardiac Output during exercise?
$120 - 150$ bpm
Where does the nervous control of Heart Rate originate from?
Medulla oblongata
Which hormone is released by sympathetic stimulation and shortens the repolarization period?
Norepinephrine
Test your knowledge on the key components and functions of the cardiac conduction system. Learn about the role of calcium channels, potassium channels, refractory periods, and neurotransmitter control in regulating heart rate and rhythm.
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