Heat
Which portion of the brain serves as the body's thermostat?
Hypothalamus
What occurs in peripheral blood vessels in response to cold?
Vasoconstriction
Where in the lungs does gas exchange occur?
Alveoli
Hb has how many O2 binding sites available?
4
Hypoxia stimulates the release of which hormone related to blood cell production? Where is this hormone released from?
EPO from the kidneys
Thermal balance is a function of which two variables?
Heat loss and heat gain
The air temperature is 35F with a wind chill of 10F and it is raining. Are you at higher risk of hypothermia or frostbite in these conditions? Why?
Hypothermia
What is the difference between the conducting and respiratory portions of the respiratory system?
Conducting = air movement
Respiratory = gas diffusion
Describe shunt perfusion vs. dead space ventilation as they relate to V/Q ratio.
Shunt perfusion = low ratio: ventilation without adequate perfusion
Dead space ventilation = high ratio: perfusion without adequate ventilation
Are acute adaptations to altitude generally positive or negative in terms of exercise performance?
Negative
What are the four ways that heat can leave the body?
Radiation, Convection, Conduction, Evaporation
How much faster do you cool in water than you would in air of the same temperature?
20-25x faster
There are five primary functions of the respiratory system, name four of them:
Providing surface area for gas exchange
Moving air to and from the exchange surfaces of the lungs
Protecting respiratory surfaces from dehydration, temp changes, and pathogen invasion
Producing sounds for communication
Detecting smells by olfactory receptors in the superior portions of the nasal cavity
What are the three ways in which CO2 can be transported in the body?
Dissolved in plasma
Bound to Hb
As bicarbonate ion
Describe why increased mitochondrial density and capillarization would be an expected response to chronic hypoxic exposure:
Capillarization allows more O2 diffusion and higher mitochondrial density increases ATP production
What are the three stages of exercise hyperthermia?
Compensation, Crisis, Failure
Compared to white adipose tissue, does brown fat have HIGHER or LOWER metabolic activity?
Higher
Compared to skeletal muscle, arterial blood has a higher or lower concentration (partial pressure) of oxygen?
Higher
Which enzyme aids in the conversion of water and CO2 into carbonic acid?
Carbonic anhydrase
Decrease plasma volume and increase relative percentage of hematocrit
Explain why CO is able to be maintained during submax exercise in the heat, but decreases during maximal exercise
Reductions in SV cannot be overcome by increases in HR once HR is at max
In the cold, O2/Hb affinity should (increase or decrease)? Why does this not always occur in practice during cold weather exercise?
Affinity should increase. Blood temp increases during exercise which negates this effect.
Which factors decrease oxyhemoglobin affinity?
Decrease in pH
Increases in temp, 2,3-DGP, CO2
Describe how changes in environment between lung and tissue allows easy removal of CO2 in the lungs and binding of O2 to bring to tissues:
High O2 concentration = low Hb affinity for CO2 (ie in the lungs)
Low O2 concentration = high affinity for CO2 (ie in working tissues)
In the article from Monday's discussion, researchers determined that SaO2 during max exercise at sea level was a major determinant of 3000m performance at altitude.
What was the relationship between SaO2 and altitude performance?
Lower SaO2 at sea level corresponded to worse performance during the altitude 3000m run test