Related Experiment Video
Updated: Jan 24, 2026

Acquisition and Semi-Automated Analysis of Respiratory Muscle Surface Electromyography
Published on: January 24, 2025
Relation between work output of respiratory muscles and end-tidal CO2 tension
Abstract:
End-tidal CO2 tension, pulmonary ventilation, and work output of respiratory muscles were determined in six normal subjects breathing various mixtures of carbon dioxide in air, with three graded resistances added to both inspiration and expiration. In two individuals, the resistances were also added separately to inspiration or expiration. A linear relationship was found between work output of inspiratory muscles and end-tidal CO2 tension; this relationship was uninfluenced by added resistance. No consistent relationship was observed between either ventilation or work output of expiratory muscles and end-tidal CO2 tension. These results suggest that carbon dioxide controls directly the activity of inspiratory muscles alone and that the activity of expiratory muscles is only coincidentally involved. The possible role of intrinsic properties of respiratory muscles and of nervous mediation in the control of breathing is discussed.
More Related Videos
09:37Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment RMCA in Individuals with Chronic Spinal Cord Injury
Published on: July 19, 2013
05:28Electrophysiology on Isolated Brainstem-spinal Cord Preparations from Newborn Rodents Allows Neural Respiratory Network Output Recording
Published on: November 19, 2015
Related Concept Videos
Tidal Forces
Tension
Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...