Altitude

Question 1

What does acute ascent to altitude result in?

Answer 1

Environmental hypoxia

Question 2

What is the reduction in the amount of oxygen due to

Answer 2

Reduced barometric pressure at increasing altitudes

Question 3

How does barometric pressure change partial pressure of inspired oxygen

Answer 3

The lower barometric pressure reduces the partial pressure of inspired oxygen

Question 4

Hypobaric Hypoxia

Answer 4

The hypoxia associated with terrestrial altitude exposure

Question 5

What is the percentage of oxygen in ambient air

Answer 5

Constant at 20.93% regardless of the altitude

Question 6

T/F the percentage of oxygen in boulders is less than at sea level

Answer 6

False

Question 7

What is the PiO2 in boulder (1630m)

Answer 7

122 mmHg

Question 8

What is the PiO2 at sea level

Answer 8

149 mmHg

Question 9

What three parameters need to be considered to to calculate PiO2

Answer 9

1. Barometric pressure
2. Water vapor pressure
3. Percentage of oxygen in the environment

Question 10

What is barometric pressure dependent on

Answer 10

Altitude

Question 11

What is water vapor pressure (PH2O) in inspired air

Answer 11

47 mmHg independent on altitude

Question 12

Sea level PiO2 calculation

Answer 12

(760 mmHg - 47 mmHg) * 0.2093= 149 mmHg

Question 13

How does acute reduction in PiO2 affect oxygen levels in the blood?

Answer 13

Reduced PiO2 leads to a decrease in alveolar partial pressure of oxygen which leads to a reduction in the partial pressure of oxygen in arterial blood

Question 14

What is the pressure of oxygen in arterial blood (PaO2) determinant of?

Answer 14

Major determinant of arterial hemoglobin O2 saturation (SaO2)

Question 15

What happens at the top of the hemoglobin oxygen dissociation curve?

Answer 15

Small changes in PaO2 have minimal effect on SaO2

Question 16

What happens at the steep portion of the hemoglobin oxygen dissociation curve?

Answer 16

Small changes in PaO2 have large effects of SaO2

Question 17

What is arterial oxygen content (CaO2) determined by

Answer 17

Hemoglobin concentration, SaO2, and the amount of oxygen dissolved in the plasma

Question 18

What is PaO2’s influence on SaO2

Answer 18

PaO2 determines the amount of oxygen dissolved in the plasma which reflects the saturation

Question 19

What is the difference between the amount of O2 dissolved in the plasma compared to bound to hemoglobin

Answer 19

The amount of O2 dissolved in plasma is extreamly small compared to the amount bound to hemoglobin

Question 20

What physiological effects occur in response to the decrease in PaO2, SaO2 and CaO2 with altitude

Answer 20

Impacts the cardiovascular, respiratory, and immune systems as well as impacts substrate utilization

Question 21

What happens to VO2 max at acute altitude exposure

Answer 21

VO2 max is reduced with the severity of the reduction greater at higher elevations.

Question 22

What effect does the reduction of VO2 max have on intensity

Answer 22

Increases the relative intensity of any given absolute power output at altitude

Question 23

Difference in VO2 max differences depending on training status at altitude

Answer 23

Trained athletes have a greater reduction in VO2 max

Question 24

What response does heart rate have at acute altitude exposure

Answer 24

Increase in resting heart rate and an elevation in heart rate at any given absolute submaximal power output

Question 25

What happens to maximal heart rate at acute altitude exposure?

Answer 25

No change

Question 26

How is the ventilatory response regulated at acute altitude

Answer 26

Peripheral chemoreceptors that reside in the aortic and carotid bodies respond to low PaO2 during hypoxia

Question 27

What happens to ventilation patterns at altitude?

Answer 27

Decrease PaO2 results in an increase in ventilation at rest and all absolute workloads

Question 28

What changes happen to substrate utilization at altitude

Answer 28

Increases in carbohydrate utilization during absolute submaximal exercise intensities

Question 29

MAP response to acute altitude exposure

Answer 29

MAP may decrease due to reductions in TRP and blood pressure

Question 30

Hypoxia in the lab setting

Answer 30

<20.93 % gas mixture

Question 31

Normobaric hypoxia

Answer 31

Pressure is normal but the PiO2 is reduced due to artificial reduction in the percentage of inspired oxygen

Question 32

What components of arterial oxygen content would be most affected by blood doping

Answer 32

Hemoglobin concentration increases

Question 33

What components of arterial oxygen content would be relatively unaffected by blood doping

Answer 33

Hemoglobin saturation and the rate of hemoglobin unloading to the tissues

Question 34

2 mechanisms which increased sympathetic activity may increase oxygen delivery with acute altitude exposure

Answer 34

Increased HR and ventilation; increase BP with exercise