Please Answer All Questions 1. Mark lives at sea level in Miami, Florida and is
ID: 86365 • Letter: P
Question
Please Answer All Questions
1. Mark lives at sea level in Miami, Florida and is planning to hike Pikes Peak at an altitude of 14,000 feet.
Which of the following statements are true about the environmental differences between sea level and high-altitude environments? Select all of the truestatements.
a. Cities at sea level tend to have an average barometric pressure of 430 mmHg
b. As partial pressure of oxygen decreases, it becomes more difficult for the body to deliver adequate oxygen throughout the body.
c. At higher altitudes, the atmosphere has a reduced ratio of oxygen to carbon dioxide.
d. As altitude increases, typical air temperature decreases.
e. Regardless of elevation, the Earth's atmosphere is always comprised of 21% oxygen.
f. Reduced barometric pressure increases oxygen availability in the blood.
g. As altitude increases, barometric pressure decreases.
2. What happens to stroke volume and maximal heart rate as people grow older?
a. They decline
b. They increase
c. The stay the same
d. SV increases and Max HR decreases
3. Dehydration further complicates exercise in the heat because a reduced blood plasma volume further hinders the body's ability to sweat and dissipate excess heat.
True or False
4. Depending on the environment, heat can be lost or gained through various channels. Which of the following statements are true about heat transfer during exercise? Select all that apply.
a. Wind increases heat loss via convection
b. Convection occurs when sun rays heat the body on hot days.
c. On hot days, heat can be radiated from the ground to the body.
d. Heat produced by active muscles is picked up by circulating blood and transported to other parts of the body.
e. Environmental heat stress can be measured by air temperature alone
5. Physical activity produces body heat and helps winter sport athletes stay warm in cold environments. However, they are still at risk for cold stress. What factors can contribute to an athlete losing heat faster than they can produce it? Select all that apply.
a. Non shivering thermogenesis causes them to lose body heat at a fast rate
b. As they become tired and reduce exercise intensity, they produce less heat and may get colder more quickly.
c. Sweat can soak through clothing and increase the rate of heat loss.
d. Vasoconstriction of peripheral blood vessels causes them to lose heat at a faster rate
e. Wind can increase convective and evaporative heat loss.
6. Which of the following adaptations occur after spending three weeks or more at high altitude? Select all that apply.
a. Red blood cell production increases
b. Muscle mass is lost
c. Hydration level decreases
d. Blood volume increases
e. Maximal heart rate decreases
f. Cardiac output drastically increases
g. Cardiac output decreases
7. Mark lives at sea level and has just arrived at high altitude. What will happen to his breathing rate in this changed environment? Why does this occur?
a. His breathing rate will increase to offset the effects of a reduced oxygen-to-carbon-dioxide ratio in the atmosphere.
b. His breathing rate will decreases due to a decrease in blood pressure and stroke volume.
c. His breathing rate will decrease in an attempt to conserve oxygen.
d. His breathing rate will increase to offset the effects of a reduced partial pressure of oxygen in the atmosphere.
8. What causes heat exhaustion?
a. A dangerously low heart rate combined with lack of sleep.
b. Increased heart rate and cardiac output combined with increased blood volume.
c. A dehydration-induced reduction in cardiac output.
d. High altitude combined with temperatures above 80 degrees Fahrenheit.
9. Mary is exercising outside on a hot humid day and is sweating a lot. What statement is likely true about Mary's condition?
a. Mary is likely experiencing an increased blood plasma volume due to dehydration.
b. Mary is likely experiencing non-shivering thermogenesis due to the temperature.
c. Mary's ability to thermoregulate is limited because sweat is less able to evaporate in humid environments
d. Mary's risk for heat stress is reduced due to the humid air and a high sweat rate.
10. Which of these physiological adaptations is not likely to occur in children in response to an exercise program?
a. Improved VO2Max
b. Increased ATP levels
c. An increase in lean body mass
d. A decrease in body weight
11. How can skin arterioles contribute to thermoregulation?
a. Skin arterioles vasodilate in cold environments
b. Skin arterioles produce sweat
c. Skin arterioles vasodilate in hot environments
d. Skin arterioles vasoconstrict in hot environments
12. Mary is aware of the many ways the body adapts to training at high altitudes. She is a competitive runner and wonders if training in high-altitude environments will help her performance at sea level. Based on discussion in the book, can Mary improve her performance at sea level with this training strategy?
a. Yes
b. Only if she trains at high altitude for at least one year.
c. No
13. Which of the following statements are true about the physiological differences between children and adults when it comes to exercise? Select all that apply.
a. Children sweat less and may be at a greater risk for heat stress.
b. Children tend to have a lower VO2Max then adults do.
c. Children can perform aerobic exercise, but should always avoid strength training.
d. Children have a greater maximal heart rate because they have smaller hearts and stroke volumes.
e. When compared to adults, children have lower maximal heart rates.
Explanation / Answer
1) At sea level, the atmospheric pressure is 760 mm of mercury. Atmospheric pressure decreases with increase in altitude but the fraction of oxygen in air remains constant for about 100 km. So, the partial pressure of oxygen decreases with increase in altitude. At high altitudes, oxygen availability in the blood decreases and it becomes more difficult for the body to deliver adequate oxygen throughout the body. To compensate for low partial pressure of oxygen at high altitudes, body responds by increasing respiratory rate and depth along with increase in heart rate and cardiac output. The temperature decreases with increasing altitude. The rate of decrease in temperature is 6.5 degree celcius for every one km rise in altitude.
So, the true statements are b, d and g.