Related Experiment Video
Updated: Oct 7, 2026

Fast and Accurate Exhaled Breath Ammonia Measurement
Published on: June 11, 2014
[Effect of histamine on duration of phases of the respiration cycle]
E N Kriukova1, A V Karpushev, S A Frolova
1St. Petersburg State University, 199034, St. Petersburg, Universitetskaya Nab., 7/9, Russia.
Abstract:
Histamine produced either a bronchodilation or a bronchoconstriction in rats. In a 0.01-1.0 mcg/ml concentration histamine augmented the contractions amplitude in electrical stimulation of the trachea, in a 10-100 mcg/ml concentration histamine enhances the muscle tone thus decreasing the induced contractions. The histamine effects seems to be connected with its prevailing influence on different structures of the airways depending on the concentration. Its high concentrations act directly on the smooth muscle whereas its lower concentration affects receptors signaling the functional modules of the metasympathetic nervous system within the intramural ganglia of the trachea.
Related Concept Videos
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Factors Affecting Respiration
Other Factors Affecting Respiration Centers
However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,...
Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
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...
Respiratory Volumes and Capacities I
