ventilation and ventilatory thresholds Flashcards
chemoreceptors
stimulated by co2 rises in cerebrospinal fluid
where are peripheral chemoreceptors
aortic bodies, carotid bodies
sensitive to blood Po2 Pco2
why are chemoreceptors ion aortic and carotid bodies
want a central picture
when Po2 decreases, ventilation
increases
how does coordination between respiratory and cardiovascular systems occur
via involuntary regulation of pulmonary ventilation
how to control ph by breathing
H ions produced
muscle buffer bicarbonate
forms carbonic acid
diffuses out and into lungs
associate to CO2 and H2O
(remove proton and ph increases)
ventilation and ph
increased ventilation = co2 exhalation = reduce blood pco2 and H+
decrease = opposite
during point exerciseโฆ
ventilation increases disproportionately to oxygen consumption
what is the disproportionate increase in ventilation during incremental exercise associated with
Venous blood PCO2 increases and needs removing
aerobic ventilation threshold (VT1)
ratio between ventilation and VO2
VE/VO2
the point where VO2 and VCO2 cross
If ๐E = 60 L/min; ๐O2 = 1.6 L/min and
๐CO2= 1.7 L/min, the ventilatory equivalent
for O2 and CO2 are
37.5 and 35.3
aerobic ventilatory threshold
remains constant and starts to increase at aerobic ventilatory threshold as o2 demand keeps increasing linearly whilst a break point in VE
The aerobic ventilatory threshold (VT1) is found at
approximately the same intensity lactate begins to accumulate in the blood (=lactate threshold) โ WHY
Hydrogen ions are formed and buffered, the resulting CO2 needs to be blown off
VT2 / respiratory compensation point
2nd break point in ventilation curve
maximal lactate steady state (MLSS)
Highest intensity at which:
lactate production = lactate removal
