An alternate explanation for the permeability changes induced by electrical impulses in vesicular membranes

1973 ◽  
Vol 14 (1) ◽  
pp. 193-196 ◽  
Author(s):  
Robert J. Turnbull ◽  
E. Neumann ◽  
K. Rosenheck
Keyword(s):  
Permeability Changes ◽  
Alternate Explanation ◽  
Electrical Impulses

Reaction response of Urchin (Echinoidea) according to the electrical impulses

2017 ◽  
Vol 10 (1) ◽  
pp. 32-37
Author(s):  
Hyeokjoon NA ◽  
Taeyun KANG ◽  
Yongbeom PYEON ◽  
Kyounghoon LEE
Keyword(s):  
Electrical Impulses

scholarly journals Assembly of the Cardiac Pacemaking Complex: Electrogenic Principles of Sinoatrial Node Morphogenesis

2021 ◽  
Vol 8 (4) ◽  
pp. 40
Author(s):  
Marietta Easterling ◽  
Simone Rossi ◽  
Anthony J Mazzella ◽  
Michael Bressan
Keyword(s):  
Cardiac Tissue ◽  
Sinoatrial Node ◽  
Cardiac Pacemaker ◽  
Tissue Level ◽  
Rhythmic Contraction ◽  
Entire Volume ◽  
Impulse Generation ◽  
Cardiac Pacemaking ◽  
Electrical Impulses ◽  
Sufficient Strength

Cardiac pacemaker cells located in the sinoatrial node initiate the electrical impulses that drive rhythmic contraction of the heart. The sinoatrial node accounts for only a small proportion of the total mass of the heart yet must produce a stimulus of sufficient strength to stimulate the entire volume of downstream cardiac tissue. This requires balancing a delicate set of electrical interactions both within the sinoatrial node and with the downstream working myocardium. Understanding the fundamental features of these interactions is critical for defining vulnerabilities that arise in human arrhythmic disease and may provide insight towards the design and implementation of the next generation of potential cellular-based cardiac therapeutics. Here, we discuss physiological conditions that influence electrical impulse generation and propagation in the sinoatrial node and describe developmental events that construct the tissue-level architecture that appears necessary for sinoatrial node function.

scholarly journals Crackle Pitch Rises Progressively during Inspiration in Pneumonia, CHF, and IPF Patients

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Andrey Vyshedskiy ◽  
Raymond Murphy
Keyword(s):  
Heart Failure ◽  
Lung Volume ◽  
Interstitial Fibrosis ◽  
Lung Sounds ◽  
Lung Sound ◽  
Lung Volumes ◽  
Alternate Explanation ◽  
40 Hz

Objective. It is generally accepted that crackles are due to sudden opening of airways and that larger airways produce crackles of lower pitch than smaller airways do. As larger airways are likely to open earlier in inspiration than smaller airways and the reverse is likely to be true in expiration, we studied crackle pitch as a function of crackle timing in inspiration and expiration. Our goal was to see if the measurement of crackle pitch was consistent with this theory.Methods. Patients with a significant number of crackles were examined using a multichannel lung sound analyzer. These patients included 34 with pneumonia, 38 with heart failure, and 28 with interstitial fibrosis.Results. Crackle pitch progressively increased during inspirations in 79% of all patients. In these patients crackle pitch increased by approximately 40 Hz from the early to midinspiration and by another 40 Hz from mid to late-inspiration. In 10% of patients, crackle pitch did not change and in 11% of patients crackle pitch decreased. During expiration crackle pitch progressively decreased in 72% of patients and did not change in 28% of patients.Conclusion. In the majority of patients, we observed progressive crackle pitch increase during inspiration and decrease during expiration. Increased crackle pitch at larger lung volumes is likely a result of recruitment of smaller diameter airways. An alternate explanation is that crackle pitch may be influenced by airway tension that increases at greater lung volume. In any case improved understanding of the mechanism of production of these common lung sounds may help improve our understanding of pathophysiology of these disorders.

scholarly journals A multi-scale approach to describe electrical impulses propagating along actin filaments in both intracellular andin vitroconditions

RSC Advances ◽  
2018 ◽  
Vol 8 (22) ◽  
pp. 12017-12028 ◽  
Author(s):  
Christian Hunley ◽  
Diego Uribe ◽  
Marcelo Marucho
Keyword(s):  
Molecular Structure ◽  
Actin Filaments ◽  
Analytic Solution ◽  
Multi Scale ◽  
Biological Environment ◽  
Electrical Impulses

An innovative analytic solution accounting for the molecular structure, its biological environment, and their impact on electrical impulses along microfilaments.

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