- increase in need for ATP and energy
- Role of respiratory and cardiovascular system important for
homeostatic balance in blood PO2, PCO2 and pH.
Ventilation and Lung Volumes
- Minute ventilation = breathing frequency x tidal volume
- Measure tidal volume by doing spirometry
5 lung volumes
1. Normal breath in normal breath out, tidal volume
2. End of normal inspiration and max inspiration, inspiratory
reserve volume
3. Di erence between end of expiration and end of maximal
expiration, expiratory reserve volume
4. Residual volume, amount of air that will stay in lungs no matter
how hard you try to empty it, alveoli would collapse without
residual volume.
5. Total lung capacity, sum of residual volume + expiratory reserve
volume + inspiratory reserve volume + tidal volume
Lung Volumes during Exercise
- End inspiratory lung volume increases as you increase intensity
of exercise.
- End inspiratory volume starts to plateau during heavy and
maximal exercise.
- Reserve volume left, you will not reach maximal capacity and
this is usually common in athletes.
- End expiratory lung volume decreases as intensity of exercise
increases.
Aerobic Metabolism
- glycogen is used as a substrate for energy production.
- CO2 released from the breakdown of pyruvic acid into acetyl
CoA
- CO2 released from Krebs cycle
- Ventilation gets rid of this CO2
ff
, Pulmonary Ventilation during Constant Load Exercise
- Exercise = increase in ventilation
- This response is neurally mediated, instant response for
increase in ventilation.
- Ventilation will stabilise depending on exercise intensity, how
much oxygen is required, how much CO2 is produced.
- The blood gases, arterial O2 content, arterial CO2 content and
pH are maintained close to the baseline range.
- Chemoreceptors will sense chance in blood gases and will
stimulate respiratory centre to help release CO2 out of the body.
Ventilatory drift
- Contribution of aerobic metabolism to energy production, regular
increase in ventilation.
Ventilatory Response to Incremental Exercise
- Ventilation increases with intensity of exercise
VENTILATORY THRESHOLD
- There is a disproportionate increase in ventilation compared to
the intensity of exercise.
- Beyond ventilatory threshold, it increases ventilation
disproportionately in order to clear excess CO2.
Anaerobic Glycosis
- If there’s not enough oxygen as glucose/glycogen breaks down
into pyruvic acid, it will turn into lactic acid.
- Lactic acid will disassociate into the muscle turning into lactate
and hydrogen.
- If pH becomes more acidic, it will block enzymatic reactions that
are key for ATP production.
- Muscle will have problems contracting if pH becomes too acidic.
- Ventilation will help get rid of excess hydrogen production.
- Hydrogen ions can be transferred to CO2 molecules and get
released from body.