Related Experiment Video
Updated: Oct 3, 2026

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Rate of change of alveolar carbon dioxide and the control of ventilation during exercise
Abstract:
The relationship between rate of change of alveolar PCO2 (delta PA, CO2/delta te), CO2 output (VCO2) and ventilation (VE) has been determined following a rapid increase in exercise intensity, to test the hypothesis that VE is related to VCO2 by a feed-forward control system responding to delta PA, CO2/delta te. There was a close relationship between delta PA, CO2/delta te and VCO2 (delta PA, CO2/delta te = 3.2 VCO2 + 0.85), but delta PA, CO2/delta te increased more rapidly than VCO2. Increases in mean inspiratory flow, an index of inspiratory drive, were more closely related to changes in delta PA, CO2/delta te than to changes in VCO2. Increases in VE during transient and steady-state conditions may be described by the equation: VE = 6.76 delta PA, CO2/delta te -3.50, a relationship which is consistent with a feed-forward control system.
More Related Videos
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Respiratory Volumes and Capacities
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Respiratory Regulation of Acid-Base Balance
When carbon dioxide levels increase in the blood, more H+ and HCO3⁻ are produced, leading to a...

