a. Explain how the gastrointestinal blood loss caused a reduction in human’s arterial pressure.
b. Why is human being’s arterial pressure is lower in the upright (standing) position than in the supine (laying down) position?
c. In supine (laying down) position, a human being’s heart rate is elevated to (105 beats/min). Why? Why human being’s heart rate is even more elevated to (135 beats/min) in upright (standing) position? Explain the mechanism here.