Cardiac Muscle and Heart Function:
Anatomy, Physiology, and Regulation
Exam With Detailed Questions And
Correct Answers||Latest Exam 2026-
2027||Already Graded A+
What type of muscle is cardiac muscle similar to in terms of striation? -CORRECT
ANSWER Cardiac muscle is striated in the same manner as skeletal muscle.
What are the two main functions of the heart? -CORRECT ANSWER The right heart
pumps blood through the lungs, and the left heart pumps blood through the systemic
circulation.
What are the two chambers of each side of the heart? -CORRECT ANSWER Each side
of the heart consists of an atrium and a ventricle.
What is the role of the atrium in the heart? -CORRECT ANSWER The atrium acts as a
weak primer pump for the ventricle, helping to move blood into the ventricle.
What surrounds the heart and protects it? -CORRECT ANSWER The heart is surrounded
by a two-layer sac called the pericardium.
What is cardiac rhythmicity? -CORRECT ANSWER Cardiac rhythmicity refers to the
continuing succession of contractions caused by action potentials throughout the
cardiac muscle.
How does the left ventricle aid in blood ejection? -CORRECT ANSWER The left
ventricle's complex muscle fiber layers allow for a twisting motion during systole, aiding
in ejection and relaxation.
What is the significance of the intercalated discs in cardiac muscle? -CORRECT
ANSWER Intercalated discs are cell membranes that connect individual cardiac muscle
cells, allowing rapid transmission of action potentials.
What are the three major types of cardiac muscle? -CORRECT ANSWER The three
types are atrial muscle, ventricular muscle, and specialized excitatory and conductive
muscle fibers.
How do specialized excitatory and conductive fibers function in the heart? -CORRECT
ANSWER They exhibit automatic rhythmical electrical discharge and conduct action
potentials, controlling the heart's rhythmical beating.
, What is the role of gap junctions in cardiac muscle? -CORRECT ANSWER Gap junctions
allow rapid diffusion of ions and facilitate the spread of action potentials between
cardiac muscle cells.
What are the two functional syncytia of the heart? -CORRECT ANSWER The atrial
syncytium and the ventricular syncytium.
What separates the atria from the ventricles in the heart? -CORRECT ANSWER Fibrous
tissue surrounds the atrioventricular (A-V) valvular openings.
How is the action potential in a ventricular muscle fiber characterized? -CORRECT
ANSWER It averages about 105 millivolts, rising from approximately -85 millivolts to +20
millivolts during each beat.
What causes the prolonged action potential in cardiac muscle? -CORRECT ANSWER
Differences in membrane properties between cardiac and skeletal muscle account for
the prolonged action potential and plateau.
How much longer can ventricular contraction last in cardiac muscle compared to
skeletal muscle? -CORRECT ANSWER Ventricular contraction can last up to 15 times
longer in cardiac muscle.
What happens to the left ventricle at the end of systole? -CORRECT ANSWER It recoils
or untwists during diastole, allowing blood to enter the pumping chambers rapidly.
What is the significance of the plateau in the action potential of cardiac muscle? -
CORRECT ANSWER The plateau prolongs the contraction duration, allowing for effective
pumping of blood.
What causes the action potential in skeletal muscle? -CORRECT ANSWER The sudden
opening of fast sodium channels that allow sodium ions to enter the muscle fiber.
What are fast sodium channels? -CORRECT ANSWER Channels that open rapidly to
allow sodium ions to flow into the cell, remaining open for only a few thousandths of a
second.
What happens at the end of the action potential in skeletal muscle? -CORRECT
ANSWER Repolarization occurs, and the action potential is over within about another
thousandth of a second.
What types of channels are involved in the cardiac muscle action potential? -CORRECT
ANSWER Fast sodium channels and L-type calcium channels (slow calcium channels).
Anatomy, Physiology, and Regulation
Exam With Detailed Questions And
Correct Answers||Latest Exam 2026-
2027||Already Graded A+
What type of muscle is cardiac muscle similar to in terms of striation? -CORRECT
ANSWER Cardiac muscle is striated in the same manner as skeletal muscle.
What are the two main functions of the heart? -CORRECT ANSWER The right heart
pumps blood through the lungs, and the left heart pumps blood through the systemic
circulation.
What are the two chambers of each side of the heart? -CORRECT ANSWER Each side
of the heart consists of an atrium and a ventricle.
What is the role of the atrium in the heart? -CORRECT ANSWER The atrium acts as a
weak primer pump for the ventricle, helping to move blood into the ventricle.
What surrounds the heart and protects it? -CORRECT ANSWER The heart is surrounded
by a two-layer sac called the pericardium.
What is cardiac rhythmicity? -CORRECT ANSWER Cardiac rhythmicity refers to the
continuing succession of contractions caused by action potentials throughout the
cardiac muscle.
How does the left ventricle aid in blood ejection? -CORRECT ANSWER The left
ventricle's complex muscle fiber layers allow for a twisting motion during systole, aiding
in ejection and relaxation.
What is the significance of the intercalated discs in cardiac muscle? -CORRECT
ANSWER Intercalated discs are cell membranes that connect individual cardiac muscle
cells, allowing rapid transmission of action potentials.
What are the three major types of cardiac muscle? -CORRECT ANSWER The three
types are atrial muscle, ventricular muscle, and specialized excitatory and conductive
muscle fibers.
How do specialized excitatory and conductive fibers function in the heart? -CORRECT
ANSWER They exhibit automatic rhythmical electrical discharge and conduct action
potentials, controlling the heart's rhythmical beating.
, What is the role of gap junctions in cardiac muscle? -CORRECT ANSWER Gap junctions
allow rapid diffusion of ions and facilitate the spread of action potentials between
cardiac muscle cells.
What are the two functional syncytia of the heart? -CORRECT ANSWER The atrial
syncytium and the ventricular syncytium.
What separates the atria from the ventricles in the heart? -CORRECT ANSWER Fibrous
tissue surrounds the atrioventricular (A-V) valvular openings.
How is the action potential in a ventricular muscle fiber characterized? -CORRECT
ANSWER It averages about 105 millivolts, rising from approximately -85 millivolts to +20
millivolts during each beat.
What causes the prolonged action potential in cardiac muscle? -CORRECT ANSWER
Differences in membrane properties between cardiac and skeletal muscle account for
the prolonged action potential and plateau.
How much longer can ventricular contraction last in cardiac muscle compared to
skeletal muscle? -CORRECT ANSWER Ventricular contraction can last up to 15 times
longer in cardiac muscle.
What happens to the left ventricle at the end of systole? -CORRECT ANSWER It recoils
or untwists during diastole, allowing blood to enter the pumping chambers rapidly.
What is the significance of the plateau in the action potential of cardiac muscle? -
CORRECT ANSWER The plateau prolongs the contraction duration, allowing for effective
pumping of blood.
What causes the action potential in skeletal muscle? -CORRECT ANSWER The sudden
opening of fast sodium channels that allow sodium ions to enter the muscle fiber.
What are fast sodium channels? -CORRECT ANSWER Channels that open rapidly to
allow sodium ions to flow into the cell, remaining open for only a few thousandths of a
second.
What happens at the end of the action potential in skeletal muscle? -CORRECT
ANSWER Repolarization occurs, and the action potential is over within about another
thousandth of a second.
What types of channels are involved in the cardiac muscle action potential? -CORRECT
ANSWER Fast sodium channels and L-type calcium channels (slow calcium channels).
