1. An electrocardiogram(ECG) on a person shows ventricular extrasystoles. The extrasystolic beat would produce which of the following change?
(a) increased pulse pressure because heart rate is increased.
(b) increased pulse pressure because contractility is increased.
(c) decreased pulse pressure because ventricular filling time is increased.
(d) decreased pulse pressure because stroke volume is decreased.
(e) decreased pulse pressure because PR interval is increased.
2. A 24 year old woman presents to the emergency department with severe diarrhea. When she is supine,her blood pressure is 90/60 mm Hg and her heart rate is 100 beats/min. When she is moved to a standing position, her heart rate further increases to 120 beats/min. Which of the following accounts for further increase in heart rate upon standing?
(a) Decreased total peripheral resistance.
(b) Increased vasoconstriction.
(c) Increased contractility.
(d) Increased afterload.
(e) Decreased venous return.
Explanation favoring u'r answer would be better
(a) increased pulse pressure because heart rate is increased.
(b) increased pulse pressure because contractility is increased.
(c) decreased pulse pressure because ventricular filling time is increased.
(d) decreased pulse pressure because stroke volume is decreased.
(e) decreased pulse pressure because PR interval is increased.
2. A 24 year old woman presents to the emergency department with severe diarrhea. When she is supine,her blood pressure is 90/60 mm Hg and her heart rate is 100 beats/min. When she is moved to a standing position, her heart rate further increases to 120 beats/min. Which of the following accounts for further increase in heart rate upon standing?
(a) Decreased total peripheral resistance.
(b) Increased vasoconstriction.
(c) Increased contractility.
(d) Increased afterload.
(e) Decreased venous return.
Explanation favoring u'r answer would be better