Energy Metabolism - Lecture 12 Flashcards
What’s the composition of the air we inhale?
21% Oxygen
0.03% CO2
What’s the composition of the air we exhale?
17% Oxygen
3.3% CO2
To have more O2 delivered to the muscles…?
More capillaries can increase blood flow ultimately increasing oxygen delivery.
More mitochondria to deliver more oxygen
Large muscle mass requires more oxygen
Why is O2 low in expired air?
If a lot of oxygen is inhaled from air, then a sufficient amount will be extracted for the cells and other reasons before being exhaled
Where is oxygen mainly delivered to
It’s delivered to sites that need it more than others.
How does oxygen extraction work?
Oxygen follows a pressure gradient from high O2 pressure moving to low O2 pressure regions.
What is oxygen usage dependant on?
The bigger we are the more oxygen we require and use
What happens to the O2 in the muscles when exercising?
Concentration of oxygen in the muscles drop and that’s when oxygen is pulled into the muscle through diffusion
When and where is oxygen extracted?
Oxygen extraction at the capillaries and only at the tissue that are in need depending on its metabolic rate.
Fick’s Equation
VO2 = HR*SV (CaO2-CvO2)
- Calculates Oxygen consumption (VO2)
What is the CaO2 - CvO2 also known as from Fick’s Equation?
Oxygen extraction; the difference in oxygen in the arterials compared to the venous blood and how much oxygen was extracted and used in the muscle.
What does Fick’s Equation tell you?
The amount of oxygen used up for energy metabolism is equivalent to the cardiac output multiplied by the oxygen content in the arteries subtracted with the oxygen content in the veins.
VO2?
Volume of oxygen taken up and utilized by the body for energy metabolism.
How does O2 extraction become more useful as you exercise?
Mitochondria become more active (More oxygen consumption to make more ATP)
Oxygen usage increase when rate of muscle contraction…?
Increase; this causes the [O2] to drop in muscles.
Oxygen deficit
Work done anaerobically, which causes a lag in oxygen consumption at the beginning of a workout. Little bit of energy in muscles produce ATP without O2.
O2 debt
Oxygen that is used during recovery; Using the O2 that was not used at the beginning.
Why is knowing VO2Max important?
It’s a key determinant of health, predicting longevity
What’s the optimal situation for a good VO2
Deliver more blood rich with O2 and extract a greater proportion of the oxygen.
Relationship between Heart Rate and Oxygen Consumption?
Linear
Why is the relationship between HR and O2 Consumption important?
It can determine the intensity that you need to train. (If you want to train at 60% VO2Max then your Max HR should be 70%)
Age Predicted Max Heart Rate Equation
220-age
How accurate is the Max Predicted Heart Rate
Within the first 10-15 bpm.