Question

11. Tony and four of his colleagues at the hospital have formed a lottery syndicate where they each contribute $5 a week to buy a ticket in the state lottery. In the last draw their numbers came up. When he was told that the syndicate had won and he would have a share of $50 million, Tony promptly fainted. How can receiving a shock such as this cause a person to faint?

12.​Siegfried experiences a hemorrhage in an artery, and now blood is leaking out of the resulting hole. His blood pressure decreases. Explain the cardiovascular reflex responses that follow to compensate for the drop in blood pressure. (Hint: Drawing a flow chart might help organize the sequence of events).

13.​Sharon "gets the wind knocked out of her" during a skiing accident in which she attempted a jump and landed hard on her feet before tumbling over. She is conscious but breathing is labored, and she complains of pain and shortness of breath. The first aid-trained ski patrolman that comes to her aid determines that Sharon has no broken bones, nor is CNS injury likely. He places tiny tubes at her nostrils that blow air (with higher than normal percentage of oxygen) into her nose then places her on the snowmobile, and takes her to the first aid tent. Why is Sharon's breathing labored? How does the high-oxygen air help her condition?

14.​Ralph is taking SCUBA diving classes and is confused as to why he should not hold his breath under water while ascending—his instructor told him he must exhale continuously. What would you tell him?

15.​A 30 year old computer programmer has had asthma for 15 years. When she lies down at night she has spells of wheezing and coughing. She has found that she can sleep better sitting nearly upright. Upon examination her doctor finds that she has an enlarged thorax. Her lungs are overinflated on X ray. The results of the examination and pulmonary function tests are shown in the table.

Ventilation rate: 16 breaths/min	Tidal volume: 600 ml
ERV: 1000 ml	RV: 3500 ml
Inspiratory capacity: 1800 ml	Vital capacity: 2800 ml
Functional residual capacity: 4500 ml	TLC: 6300 ml

After she was given a bronchodilator, her vital capacity increased to 3650 ml.

What is her minute volume?

Why is there a change in vital capacity with bronchodilators?

16.​What other values are abnormal and why?

Marco tried to hide at the bottom of a swimming hole by breathing in and out through 2 feet of garden hose, which greatly increases his anatomic dead space. What happens to the following parameters in the arterial blood and why?

17.​PCO2​​​​

18.​PO2​​​​

19.​Bicarbonate ion​​

20.​pH​​​​

21.​Which of the following has the greatest effect on the ability of blood to transport oxygen?

A. Capacity of the blood to dissolve oxygen

B. Amount of hemoglobin in the blood

C. pH of plasma

D. CO2 content of red blood cells

E. Temperature of the blood

22.​​Premature babies frequently need to be put on a respirator to help them breathe. Why does this become a necessary treatment for many premature babies?

23.​ ​Air flow in the respiratory system and blood flow in the cardiovascular system have many similarities; name three.

24.​Erythropoietin (EPO) is a hormone produced by the kidneys and released in response to hypoxia to promote the maturation of RBCs. During the 1980s, a human recombinant form of EPO (rHuEPO) became available. Explain the advantages and dangers of administering someone rHuEPO to increase oxygen-carrying capacity of blood.

LAST QUESTION!!

a.​Take your pulse.

b.​Assuming that your SV is 70 ml and 1 ml of blood weighs 1g, calculate how long it would take your heart to pump your body weight in blood. (NB: 2.2 lbs = 1 kg).

Answer 1

Physiological shock causes a severe drop in blood pressure and rapid shallow heartbeat. Shock is the body’s first response to traumatic injury and the response is triggered by the autonomic nervous system. People often lose consciousness from traumatic injuries, and this physiological shock response is believed to be a mechanism to reduce blood loss. It would not take long to pump the body dry of blood through a serious wound if the heart was pounding wildly. It takes even less time for this to happen in a woman’s body, because she has 5-8 pints of blood compared to 8-10 pints of blood in a man’s body. No wonder females can be more prone to fainting.

Fainting from an emotional shock is iconic, especially for females. Fear and other stressful emotional states that provoke a similar shock response in the cardiovascular system that occurs after traumatic injury will cause fainting. Some people faint at the sight of blood, for example. This is believed to be in part a genetically predisposed mechanism that may have had survival value for our ancestors. Those people who had a hair-trigger response to activating this last-ditch safety mechanism to limit blood loss from trauma survived in prehistoric times long before medical first responders existed. Even seeing blood loss or seeing a hypodermic needle causing penetrating “injury” to another person can trigger fainting in these people.