Question

1. Jane was riding her horse on a warm sunny day (101 degrees Fahrenheit) when suddenly her horse stopped and reared up in the air. Jane was not prepared for this and fell hard backwards into the ground. As she hit the ground Jane's leg was gashed open by a large, sharp boulder that she fell next to. Jane began to bleed severely. Jane's pulse seems to be low and her respiratory rate is at 25 bpm. Jane's body spends the next couple hours physiologically compensating for her blood loss. Based on your knowledge of the cardiovascular system complete the following: Make a graph of Jane's cardiac output/venous return (y-axis) vs (as a function of) her central venous pressure. Provide two points on the curve that represent (A) before she fell off the horse and (B) after she fell and suffered significant bleeding. Make sure the pressures and L/min are labeled correctly one each axis. Then list any compensatory mechanisms the body is using to return the cardiac output to normal while bleeding.
2. Sarah was recently diagnosed with an obstructive lung disorder. In their diagnostic process the doctors completed a Forced Vital Capacity test on Sarah to determine her lung function. Based on this, (A) diagram a Vital Capacity test with lung volumes for a healthy individual and on the same graph include the VC test with lung volumes for Sarah's diagnosis. The doctors also found that Sarah's oxygen saturation was at 87%. Therefore, (B) diagram an oxygen saturation curve graph that shows a normal oxygen saturation curve and a curve representing Sarah's condition.

Answer 1

i. Baroreceptor Mechanism
Ischemic response by baroreceptors initiates strong sympathetic stimulation, which causes vasoconstriction and tachycardia
ii. Renal Mechanism
Kidneys release large amount of renin that increases the angiotensin II formation. Angiotensin II produce intense vasoconstriction and increases release of aldosterone from adrenal cortex. Aldosterone in turn promotes retention of water and salts by kidneys. This helps in restoration of blood volume.
iii. ADH Mechanism
Antidiuretic hormone (ADH) released from posterior pituitary increases retention of water by kidneys. ADH also enhances vasoconstriction.

second question

A

in sarah's spirogram expiratory reserve volume and vital capacity is reduced

sarah's % saturation of haemoglobin with oxygen is reduced