NR 302 EXAM 5 STUDY GUIDE
1. Define the apical impulse and describe its normal location, size, and duration.
a. The pulsation created as the left ventricle rotates against the chest wall during
systole. When visible, it occupies the fourth or fifth intercostal space, at or inside
the midclavicular line. Size; normally 1 x 2 cm. Duration; short, normally
occupies only first half of systole.
2. Which abnormal conditions may affect the location of the apical impulse?
a. Left ventricular dilation (volume overload) displaces impulse down and to the left
and increases size.
b. Sustained impulse with increased force and duration but no change in location
occurs with left ventricular hypertrophy and no dilation (pressure overload)
c. Pulmonary emphysema makes it non-palpable from the lung sound overriding
heart sound.
3. Explain the mechanism producing normal first and second heart sounds.
a. First heart sound (S1) occurs with closure of the AV valves and this signals the
beginning of systole. The mitral component of the first sound slightly precedes
the tricuspid component, but you usually hear these two components fused as one
sound. You can hear S1 over all the precordium but usually loudest at the apex.
b. Second heart sound (S2) occurs with closure of the semilunar valves and signals
the end of systole. The aortic component of the second sound (A2) slightly
precedes the pulmonic component. Although it is heard over all the precordium,
S2 is loudest at the base.
4. Describe the effect of respiration on the heart sounds.
a. During inspiration, more venous blood can enter the vena cava due to decreasing
thoracic pressure which increases the amount of blood in the right side of heart
thus increasing its volume.
5. Describe the characteristics of the first heart sounds and its intensity at the apex of the
heart and at the base.
a. Intensity depends on (1) position of AV valve at the start of systole (2) structure
of the valve leaflets, and (3) how quickly pressure rises in the ventricle.
6. Describe the characteristics of the second heart sound and its intensity at the apex of the
heart and at the base.
a. S2- "Dub"- is the loudest at the base.
7. Explain the physiologic mechanism for normal splitting of S1 in the pulmonic valve area.
1. Define the apical impulse and describe its normal location, size, and duration.
a. The pulsation created as the left ventricle rotates against the chest wall during
systole. When visible, it occupies the fourth or fifth intercostal space, at or inside
the midclavicular line. Size; normally 1 x 2 cm. Duration; short, normally
occupies only first half of systole.
2. Which abnormal conditions may affect the location of the apical impulse?
a. Left ventricular dilation (volume overload) displaces impulse down and to the left
and increases size.
b. Sustained impulse with increased force and duration but no change in location
occurs with left ventricular hypertrophy and no dilation (pressure overload)
c. Pulmonary emphysema makes it non-palpable from the lung sound overriding
heart sound.
3. Explain the mechanism producing normal first and second heart sounds.
a. First heart sound (S1) occurs with closure of the AV valves and this signals the
beginning of systole. The mitral component of the first sound slightly precedes
the tricuspid component, but you usually hear these two components fused as one
sound. You can hear S1 over all the precordium but usually loudest at the apex.
b. Second heart sound (S2) occurs with closure of the semilunar valves and signals
the end of systole. The aortic component of the second sound (A2) slightly
precedes the pulmonic component. Although it is heard over all the precordium,
S2 is loudest at the base.
4. Describe the effect of respiration on the heart sounds.
a. During inspiration, more venous blood can enter the vena cava due to decreasing
thoracic pressure which increases the amount of blood in the right side of heart
thus increasing its volume.
5. Describe the characteristics of the first heart sounds and its intensity at the apex of the
heart and at the base.
a. Intensity depends on (1) position of AV valve at the start of systole (2) structure
of the valve leaflets, and (3) how quickly pressure rises in the ventricle.
6. Describe the characteristics of the second heart sound and its intensity at the apex of the
heart and at the base.
a. S2- "Dub"- is the loudest at the base.
7. Explain the physiologic mechanism for normal splitting of S1 in the pulmonic valve area.
