Exercise Flashcards
how does oxygen move from lungs to tissue where it is consumed?
oxygen moves from lungs diffuses into capillary network in lungs (vessels in parallel) blood is picking up oxygen and getting rid of carbon dioxide
travels from lungs to heart then heart pumps blood to rest of body
what is the relationship between oxygen delivery (DO2), oxygen content, and cardiac output?
cardiac output x the oxygen content of blood = oxygen delivery
oxygen content of blood is O2 bound to hemoglobin + amount of O2 dissolved in blood
ex: patient with anemia (low hemoglobin) will have reduced oxygen content so cardiac output must increase to make up for it - poor oxygen delivery to tissues
what are the components of oxygen content?
oxygen content is made up of oxygen bound to hemoglobin and dissolved in blood
how would you describe the relationship between oxygen intake in the lungs and oxygen consumption at the tissue?
oxygen diffuses into capillary at lungs and diffuses out to tissues, muscles and organs in body
carbon dioxide diffuses into lungs to escape and picked up in tissues, muscles, organs (have to get rid of CO2)
oxygen we bring in = oxygen used by body (oxygen consumption (VO2)
a deficiency of RBC or hemoglobin
anemia
What is the relationship between respiratory quotient (RQ), volume of carbon dioxide produced (πΛπΆπ2) and volume of oxygen consumed (πΛπ2) ?
R=VCO2/VO2
they depend on what is the fuel we are burning to make energy
carbs - R = 1.0
protein - R = 0.8
fat - R = 0.7
using less oxygen as we shift fuels we are using
typical U.S. diet is about 0.8 R
The mix of fuel (protein, fat, carbs) we are using influences the RQ. How?
Each fuel has a different R value which influences how much oxygen/carbon dioxide we are going to use to burn each.
how is the intensity of exercise related to the RQ?
as the intensity of exercise increases, gradually R value increases -> getting closer to value of R=1
quick energy - we want to burn carbs (R= 1)
How does carbon dioxide elimination during exercise impact the maintenance of acid-base balance?
we may develop increase acid in system as we produce CO2
(CO2 + water -> carbonic acid -> H+ and bicarbonate) (need to get rid of CO2 which is being produced more as we get closer to R=1)
if we donβt, pH will fall
blood pH β¦ when carbohydrates (as opposed to fats/proteins) are primary fuel source during exercise. Why?
decreases
- During exercise, the body uses carbohydrates to rapidly generate energy. As the metabolic fuel switches to carbohydrates, the respiratory quotient increases to nearly 1.0, meaning that more CO2 is produced per mL of oxygen consumed. The excess CO2 generated by the tissues is released into the blood, where it combines with water to form H2CO3, which dissociates to HCO3- and H+. As the level of H+ in the blood increases, the pH drops.
more .. is produced by the metabolism of carb only diet vs fat or protein only. causing ventilation to increase to remove excess ..
carbon dioxide
as R increases towards 1, ventilation increases to get rid of CO2
How do oxygen delivery, oxygen extraction, and oxygen utilization contribute to oxygen consumption?
oxygen consumption depends on oxygen delivery and ability to take up oxygen at level of the tissue and utilize it for aerobic metabolism
Why does minute ventilation increase more rapidly as the body shifts toward anaerobic metabolism as a result of increased exercise intensity?
minute ventilation (VE) - how many L/min someone is breathing VE as a function of time - increases linearly also as VE increases VO2 (oxygen consumption) increases
intense exercise - slope becomes very steep
ventilation inc faster than O2 consumption (anaerobic processes)
point is anaerobic threshold
producing acid now during anaerobic metabolism
You are monitoring a patient undergoing an exercise physiology test. You notice that the minute ventilation begins to increase out of proportion to the oxygen consumption when she begins a particularly challenging part of the test. What is happening?
The patient has reached her anaerobic threshold and is increasing her minute ventilation to compensate for the production of metabolic acids.
How would you describe the acid-base status of an individual during the anaerobic phase of exercise (i.e. when the individual has passed the anaerobic threshold)?
primary metabolic acidosis
