Term
| When does the body switch into anaerobic metabolism? |
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Definition
| when oxygen extraction exceeds oxygen consumption |
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Term
| what is the byproduct of anaerobic metabolism? |
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Definition
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Term
| At what point does O2 consumption (VdotO2) stop increasing linearly with work rate? |
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Definition
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Term
| what is the anaerobic threshold? |
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Definition
| The point above which the muscles derive their energy from nonoxygenic rather than oxygenic sources during exercise. The body can only operate above this threshold for a short period of time, such as when sprinting, before lactic acid builds up in the muscles |
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Term
| what is another name for anaerobic threshold (AT)? |
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Definition
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Term
| How can you tell on an O2 consumption graph, where AT has been reached? |
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Definition
| the slope of total ventilation increases suddenly as a result of high levels of blood lactate that induce increased respiration rate |
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Term
| how does lactate differ from lactic acid? |
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Definition
| lactate is lactic acid that has lost a proton |
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Term
During exercise, at what rate does cardiac output (Q) increase?
At what rate does ventilation (VdotE) increase? |
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Definition
Q increases 5x
VdotE increases 30x |
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Term
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Definition
| Air at higher altitudes is less dense and therefore contains lower percentages of oxygen |
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Term
| Would a person have a higher or lower arterial pH at high altitudes? |
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Definition
higher
Why -- hypoxia at high altitudes causes hyperventilation which lowers PaCO2 and induces respiratory alkalosis |
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Term
| What chemicals does hypoxemia of high altitudes stimulate the release of? |
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Definition
erythropoietin (EPO) to stimulate production of new RBCs
2,3-DPG to decrease O2 binding affinity |
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Term
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Definition
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Term
| How long does a person have to live at high altitudes before EPO stimulates RBC production in bone marrow? |
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Definition
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Term
| Why does the hypoxic vasoconstriction reflex work to correct regional V/Q mismatches at sea level but not at high altitudes? |
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Definition
| At high altitudes, every region of the lung is hypoxic, which causes a massive vasoconstriction throughout the entire lung. |
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Term
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Definition
HAPE = high altitude pulmonary edema due to massive vasoconstriction at high altitudes. Pulmonary vascular resistance increases, backing up blood into the right ventricle and increasing pulmonary artery pressure. Therefore, the lungs are more susceptible to edema
*This can happen very quickly -- seconds to minutes |
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Term
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Definition
| HACE = high altitude cerebral edema |
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Term
| How can O2 be toxic at high levels? |
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Definition
| it can product oxygen radicals which are highly reactive with body tissues |
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Term
| What can 100% O2 cause in babies? |
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Definition
| retrolental fibroplasia = blindness :'( |
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Term
| What is absorption atelectasis? |
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Definition
| collapsing of alveolar units that already have a low V/Q ratio due to a mucous plug or other obstruction. These alveoli are normally kept open by nitrogen because nitrogen does not diffuse across the alveolar membrane very quickly, but on 100% O2, the oxygen displaces the nitrogen and will diffuse across the membrane into the blood and the alveoli will collapse |
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Term
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Definition
| the "bends," or decompression sickness, are bubbles of N2 in the blood that come out of solution while ascending from a deep dive. The N2 was dissolved due to high compressive forces during descent, but once external pressure was relieved during ascent, the nitrogen bubbles out of the blood |
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