EKG TECHNICIAN STUDY GUIDE |VERIFIED QUESTIONS AND
ANSWERS|GRADED A+|LATEST 2026/2027
Endocardium - ANSWER✔ The innermost layer of the heart, it forms the lining and folds back onto
itself to form the four valves. It is in this layer that the conduction system is found
Myocardium - ANSWER✔ Muscular layer of the heart
Epicardium - ANSWER✔ The outermost layer of the heart. It is actually the inner layer of the
pericardium
Right atrium - ANSWER✔ Receives deoxygenated blood returning to the heart from the body via the
superior vena cav which carries blood from the upper body and the inferior vena cava which carries
blood from the lower body.
Right ventricle - ANSWER✔ Receives deoxygenated blood from the right atrium which pumps to the
lungs for oxygenation through the pulmonary artery (trunk) to the right and left pulmonary arteries
Left atrium - ANSWER✔ Receives oxygenated blood returning from the lungs via the right and left
pulmonary veins.
Left ventricle - ANSWER✔ Receives the oxygenated blood from the left atrium and pumps it to the
body through the aorta, the largest artery of the body.
The two semilunar valves - ANSWER✔ Pulmonic valves and aortic valves
Heart Sounds S1 - ANSWER✔ First heart sound is due to the closure of the mitral and tricuspid valves
Heart Sounds S2 - ANSWER✔ Second heart soudn is due to closure of the aortic and pulmonic valves
, Coronary arteries - ANSWER✔ The arteries supplying the heart with blood
Sympathetic Nervous System - ANSWER✔ Affects both the ventricles and atrium by increasing heart
rate, conduction and irritability
Parasympathetic Nervous System - ANSWER✔ Affects the atria only by decreasing heart rate,
conduction and irritability
Automaticity - ANSWER✔ This is the ability of the cardiac cells to stimulate their own electrical
impulse without being stimulated from another source
Excitability - ANSWER✔ Irritability, shared by all cardiac cells and it the ability to respond to external
stimulus; electrical, chemical and mechanical
Conductivity - ANSWER✔ This is the ability of all cardiac cellls to receive and electrical stimulus adn
transmit the stimulus ot the other cardiac cells
Contractility - ANSWER✔ This is the ability of the cardiac cells to shorten and cause cardiac muscle
contraction in response to an electrical stimulus
SA node - ANSWER✔ Primary pacemaker of the heart, instrinisc rate of 60 -100 beats per minute
AV node - ANSWER✔ Located at the posterior septal wall of the right atrium, just above the tricuspid
valve. There is a 1/10th of a second delay of electrical activity at this level to allow the blood to flow
from the atria to the ventricles. Intrinsic rate of 40-60 beats per minute
Bundle of His - ANSWER✔ Found at the superior portion of the interventricular septum, it is the
pathway that leads to the SA node. Intrinsic rate 40-60 beats per minute.
Bundle Branches - ANSWER✔ Located at the interventricular septum. The bundle of His divides into
the right and left bundle branches. The function is to conduct the electrical impulse to the purkinje
fibers.
ANSWERS|GRADED A+|LATEST 2026/2027
Endocardium - ANSWER✔ The innermost layer of the heart, it forms the lining and folds back onto
itself to form the four valves. It is in this layer that the conduction system is found
Myocardium - ANSWER✔ Muscular layer of the heart
Epicardium - ANSWER✔ The outermost layer of the heart. It is actually the inner layer of the
pericardium
Right atrium - ANSWER✔ Receives deoxygenated blood returning to the heart from the body via the
superior vena cav which carries blood from the upper body and the inferior vena cava which carries
blood from the lower body.
Right ventricle - ANSWER✔ Receives deoxygenated blood from the right atrium which pumps to the
lungs for oxygenation through the pulmonary artery (trunk) to the right and left pulmonary arteries
Left atrium - ANSWER✔ Receives oxygenated blood returning from the lungs via the right and left
pulmonary veins.
Left ventricle - ANSWER✔ Receives the oxygenated blood from the left atrium and pumps it to the
body through the aorta, the largest artery of the body.
The two semilunar valves - ANSWER✔ Pulmonic valves and aortic valves
Heart Sounds S1 - ANSWER✔ First heart sound is due to the closure of the mitral and tricuspid valves
Heart Sounds S2 - ANSWER✔ Second heart soudn is due to closure of the aortic and pulmonic valves
, Coronary arteries - ANSWER✔ The arteries supplying the heart with blood
Sympathetic Nervous System - ANSWER✔ Affects both the ventricles and atrium by increasing heart
rate, conduction and irritability
Parasympathetic Nervous System - ANSWER✔ Affects the atria only by decreasing heart rate,
conduction and irritability
Automaticity - ANSWER✔ This is the ability of the cardiac cells to stimulate their own electrical
impulse without being stimulated from another source
Excitability - ANSWER✔ Irritability, shared by all cardiac cells and it the ability to respond to external
stimulus; electrical, chemical and mechanical
Conductivity - ANSWER✔ This is the ability of all cardiac cellls to receive and electrical stimulus adn
transmit the stimulus ot the other cardiac cells
Contractility - ANSWER✔ This is the ability of the cardiac cells to shorten and cause cardiac muscle
contraction in response to an electrical stimulus
SA node - ANSWER✔ Primary pacemaker of the heart, instrinisc rate of 60 -100 beats per minute
AV node - ANSWER✔ Located at the posterior septal wall of the right atrium, just above the tricuspid
valve. There is a 1/10th of a second delay of electrical activity at this level to allow the blood to flow
from the atria to the ventricles. Intrinsic rate of 40-60 beats per minute
Bundle of His - ANSWER✔ Found at the superior portion of the interventricular septum, it is the
pathway that leads to the SA node. Intrinsic rate 40-60 beats per minute.
Bundle Branches - ANSWER✔ Located at the interventricular septum. The bundle of His divides into
the right and left bundle branches. The function is to conduct the electrical impulse to the purkinje
fibers.
