Related Experiment Video
Updated: Aug 8, 2026

Determination of Cardiac Output in a Porcine Model for Ex Vivo Pulmonary Perfusion
Published on: June 28, 2024
A Direct Confirmation of the Standard Method of Estimating Intercellular Partial Pressure of CO(2)
T D Sharkey1, K Imai, G D Farquhar
1Department of Environmental Biology, Research School of Biological Sciences, Australian National University, Canberra City, A. C. T. 2601, Australia.
Abstract:
The partial pressure of CO(2) inside leaves of several species was measured directly. Small gas exchange chambers were clamped above and below the same section of an amphistomatous leaf. A flowing gas stream through one chamber allowed normal CO(2) and water vapor exchange. The other chamber was in a closed circuit consisting of the chamber, an infrared gas analyzer, and a peristaltic pump. The CO(2) in the closed system rapidly reached a steady pressure which it is believed was identical to the CO(2) pressure inside the leaf, because there was no flux of CO(2) across the epidermis. This measured partial pressure was in close agreement with that estimated from a consideration of the fluxes of CO(2) and vapor at the other surface.
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...
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
External and Internal Respiration
Gas Exchange and Transport
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...

