Explain Increased Cardiac Output
i) An increase in blood volume increases the venous return and leads to an increased stroke volume. The increase in the blood volume may be due to water retention, which may follow sodium retention, due to increased aldosterone secretion or some other factors.
ii) During exercise, the cardiac output increases due to an increase in both stroke volume and heart rate. Hence, systolic pressure generally increases during exercise.
iii) An increase in heart rate does not always alter the blood pressure because if stroke volume decreases simultaneously, cardiac output does not change significantly.
iv) Emotional excitement increases systolic, as well as, diastolic pressure because of increased sympathetic adrenal activity.