Lecture 20 Flashcards
We bring in _________ from the _______ which goes into the _______ from the _________ and we need to extract ________ from the exercising lungs
O2 atmosphere blood lungs CO2
Which is the major fueling pathway for our exercising skeletal muscles?
oxidative phosphorylation
What are the three main goals of the respiratory system during exercise?
- ensure that the _______ _______ of O2 (________) in our _______ is well maintained to allow adequate ________ supply to our _________ muscles
- to ________ metabolic and ____________ CO2 to maintain the partial pressure of ________ (_______) in our _________
- to assist in the _______ of the metabolic ______ produced during ________ intensity exercise
- ensure that the partial pressures of O2 (PaO2) in our arteries is well maintained to allow adequate O2 supply to our exercising muscles
- to eliminate metabolic and non-metabolic CO2 to maintain the partial pressure of CO2 (PaCO2) in our arteries
- to assist in the buffering of the metabolic acids produced during high intensity exercise
At sea level, the PO2 in the air is about ________ mmHg by by the time it reaches the alveoli, it is about ________mmHg.
159
105
O2 diffuses into the lung _________ and then binds to ___________
capillaires
Hb
What fueling pathway is used in the lungs? Describe this in terms of the PO2.
Oxidative phosphorylation in the lungs which uses O2
The PO2 is decreased in the muscle (40mmHg)
How much O2 do muscles extract at rest and how does this change during exercise?
at rest: about 60mmHg
during exercise: we extract much more
If there is 20mL of O2 per 100mL of blood in the artery and 4-5mL diffuses into the muscles, how much is in 100mL of blood in the vein?
Is this at rest or during exercise?
15-16mL
this is at rest
If there is 20mL of O2 per 100mL of blood in the artery and 15mL diffuses into the muscles, how much is in 100mL of blood in the vein?
Is this at rest or during exercise?
5mL
this is during exercise
What are the two main CO2 sources?
metabolic and non-metabolic pathways
What are the two metabolic pathways where CO2 comes from?
Glucose + 6O2 → 30 ATP + 6CO2 +6H2O
Palmitate + 23O2 → 108 ATP + 16 CO2
What is the non-metabolic pathway that CO2 comes from?
H+ + HCO3 →H2CO3 → CO2 + H2O
After the blood has gone through the ________ beds, we have a decrease in _________ in the __________ system that needs to be replenished in the __________ system. We also need to expel _____. During exercise, there is an increase in ________
muscle PO2 venous pulmonary CO2 ventilation
What two things increase what we increase ventilation?
- tidal volume
- breathing frequency
By how many times does the tidal volume increase from rest to maximal exercise?
it is 8 times greater
By how many times does the breathing frequency increase from rest to maximal exercise?
is it 4 times greater
By how many times does the ventilation increase from rest to maximal exercise?
it is 32 times greater
What controls the increase in ventilation during exercise?
both neural and chemical pathways
How does the respiratory rate change in anticipation for exercise?
it starts to increase so it is greater than at rest but less than during exercise
Explain why exercise is hard at first and then it gets easier
it gets easier because the neural control settles down and the chemical control takes over