HEART ANATOMY AND PHYSIOLOGY
QUESTIONS AND ANSWERS GRADED A+
2024/2025
Which branch of the ANS increases the strength of contraction within the contractile cells of the heart? -
Answer The sympathetic branch of the ANS.
Which branch of the ANS slows down HR? What neurotransmitter is used? What receptors are present
on the heart cells? - Answer The parasympathetic branch of the ANS slows down the heart rate. The
neurons release ACh which binds to muscarinic receptors on heart muscle cells.
Which branch of the ANS slows down the heart rate? - Answer Parasympathetic branch of the ANS.
Which branch of the ANS speeds up HR? What neurotransmitter is used? What receptors are present on
the heart cells? - Answer The sympathetic branch of the ANS speeds up the heart rate. The neurons
release NE which binds to beta-1 receptors on heart muscle cells.
Which ion causes the autorhythmic cardiac muscle cells to reach threshold? What type of gate do these
ions move through? – Answer Sodium ions moving through leak gates.
Which ion causes the plateau phase during an action potential in cardiac contractile muscle cells? What
type of gate do these ions move through? – Answer Calcium ions moving through voltage-regulated
gates.
Which ion causes the rapid depolarization during the action potential in cardiac contractile muscle cells?
What type of gate do these ions move through? – Answer Sodium ions moving through voltage-
regulated gates.
, Which ion causes the rapid depolarization during the action potential in the SA node conductile cells?
What type of gate do these ions move through? – Answer Calcium ions moving through voltage-
regulated gates.
Which ion causes the rapid repolarization during the action potential in cardiac contractile muscle cells?
What type of gate do these ions move through? – Answer Potassium ions moving through voltage-
regulated gates.
Which ion causes the rapid repolarization during the action potential in the SA node conductile cells?
What type of gate do these ions move through? – Answer Potassium ions moving through voltage-
regulated gates
Which valves are closing during the "dub" part of "lub-dub"? – Answer The semilunar valves (pulmonary
and aortic valves) are closing during the "dub" sound.
What does diastole mean? – Answer Diastole is the relaxation of a heart chamber. There is atrial diastole
and ventricular diastole.
What does systole mean? – Answer Systole is the contraction of a heart chamber. There is atrial systole
and ventricular systole.
What effect does an increase in afterload have on CO? – Answer An increase in afterload decreases CO.
What effect does an increase in preload have on CO? – Answer An increase in preload increases CO.
What is a cardiac cycle? – Answer One complete contraction and relaxation of the atria and the
ventricles.
What is cardiac output? – Answer The amount of blood that is ejected per minute. CO = SV x HR
SV = stroke volume
HR = heart rate
QUESTIONS AND ANSWERS GRADED A+
2024/2025
Which branch of the ANS increases the strength of contraction within the contractile cells of the heart? -
Answer The sympathetic branch of the ANS.
Which branch of the ANS slows down HR? What neurotransmitter is used? What receptors are present
on the heart cells? - Answer The parasympathetic branch of the ANS slows down the heart rate. The
neurons release ACh which binds to muscarinic receptors on heart muscle cells.
Which branch of the ANS slows down the heart rate? - Answer Parasympathetic branch of the ANS.
Which branch of the ANS speeds up HR? What neurotransmitter is used? What receptors are present on
the heart cells? - Answer The sympathetic branch of the ANS speeds up the heart rate. The neurons
release NE which binds to beta-1 receptors on heart muscle cells.
Which ion causes the autorhythmic cardiac muscle cells to reach threshold? What type of gate do these
ions move through? – Answer Sodium ions moving through leak gates.
Which ion causes the plateau phase during an action potential in cardiac contractile muscle cells? What
type of gate do these ions move through? – Answer Calcium ions moving through voltage-regulated
gates.
Which ion causes the rapid depolarization during the action potential in cardiac contractile muscle cells?
What type of gate do these ions move through? – Answer Sodium ions moving through voltage-
regulated gates.
, Which ion causes the rapid depolarization during the action potential in the SA node conductile cells?
What type of gate do these ions move through? – Answer Calcium ions moving through voltage-
regulated gates.
Which ion causes the rapid repolarization during the action potential in cardiac contractile muscle cells?
What type of gate do these ions move through? – Answer Potassium ions moving through voltage-
regulated gates.
Which ion causes the rapid repolarization during the action potential in the SA node conductile cells?
What type of gate do these ions move through? – Answer Potassium ions moving through voltage-
regulated gates
Which valves are closing during the "dub" part of "lub-dub"? – Answer The semilunar valves (pulmonary
and aortic valves) are closing during the "dub" sound.
What does diastole mean? – Answer Diastole is the relaxation of a heart chamber. There is atrial diastole
and ventricular diastole.
What does systole mean? – Answer Systole is the contraction of a heart chamber. There is atrial systole
and ventricular systole.
What effect does an increase in afterload have on CO? – Answer An increase in afterload decreases CO.
What effect does an increase in preload have on CO? – Answer An increase in preload increases CO.
What is a cardiac cycle? – Answer One complete contraction and relaxation of the atria and the
ventricles.
What is cardiac output? – Answer The amount of blood that is ejected per minute. CO = SV x HR
SV = stroke volume
HR = heart rate
