Respiratory Responses Flashcards
What is the role of central chemoreceptors?
Stimulated by an increase in CO2 and cerebrospinal fluid.
Stimulates inspiratory system to increase breathing rate and depth.
What is the role of peripheral chemoreceptors?
Sensitive to blood PCO2, PO2, and pH.
Found in aortic/carotid bodies.
Stimulate inspiratory system.
What is the role of the receptors in the right ventricle of the heart?
Detects changes -> sends signals to the inspiratory centre.
Inspiratory centre increases Q which stimulates increased breathing rate during early stages of exercise.
Humoral influence.
Overall, gradual respiratory increase is controlled by what changes?
Changes in the chemical status (pH) of arterial blood.
An increased ventilatory rate, during heavy exercise leads to what?
- CO2 exhaustion/expelling
- Reduction in blood PCO2
- Increase in pH (decrease in H+ concentration)
An decreased ventilatory rate, during heavy exercise leads to what?
- CO2 build up
- Increase in blood PCO2
- Decrease in pH (increase in H+ concentration)
Post-exercise recovery takes several minutes and breathing rate remains elevated. What three factors regulates this process?
- Acid-base balance
- PCO2
- Blood temperature
State the process of removal of CO2 from the lungs, starting from the accumulation of H+.
- Increase in H+ concentration in the blood.
- Stimulation of inspiratory centre.
- Binding of bicarbonate to H+ ions to produce CO2 and H2O in the lungs.
- CO2 expelled out of the lungs by an increased ventilation rate.
- Excess H+ removed via kidney excretion.
What is the ventilatory equivalent for oxygen?
The ratio between minute ventilation and VO2.
What is acidosis?
H+ concentration above normal (low pH)
What is alkalosis?
H+ concentration below normal (high pH)
What is the difference between ventilatory threshold 1 and respiratory compensation point?
VT1 is the point during sub-maximal exercise where ventilation increases disproportionately to oxygen consumption.
VT1 is found around LT1.
RCP is found where the second break point in ventilation occurs due to insufficient buffering of lactic acid.
RCP occurs around MLSS
What are ventilatory thresholds used widely to predict?
Performance and training plans
What is the V-slope method determining at which point VT1 occurs?
Draw two regression lines, following the trends of VCO2 as a function of VO2.
Where these lines intersect is VT1.
What other two factors can be used to determine VT1?
- First proportionate increase in RER.
- First increase in the expiratory fraction of O2.
