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Breathing Control in Exercise
Published in Susmita Chowdhuri, M Safwan Badr, James A Rowley, Control of Breathing during Sleep, 2022
The matching between alveolar ventilation and pulmonary gas exchange observed during exercise is the result of a complex process wherein the ventilatory strategy “chosen” by the central nervous system is determined by (1) the magnitude and kinetics of the feedback inputs, which are the direct or indirect, but still poorly understood, consequences of the changes in gas exchange or one of its surrogates, (2) central mechanisms selecting, filtering or favoring certain of these inputs. These interactions lead to an apparently very simple ventilatory response that follows the gas exchange rate, preserving arterial blood gas homeostasis. The enormous body of literature generated over one century to understand this question has not brought a definitive answer to this challenging question. As a result, one must consider the rather pessimist conclusion that no conceptual framework can currently be used to understand how A can increase in proportion to a rise in the pulmonary gas exchange rate.
Pulmonary gas exchange
Published in Andrew M. Luks, Philip N. Ainslie, Justin S. Lawley, Robert C. Roach, Tatum S. Simonson, Ward, Milledge and West's High Altitude Medicine and Physiology, 2021
Andrew M. Luks, Philip N. Ainslie, Justin S. Lawley, Robert C. Roach, Tatum S. Simonson
The most important feature of pulmonary gas exchange at high altitude is the increase in minute and, as a result, alveolar ventilation and its consequences. The importance of hyperventilation is emphasized if we look at its role at extreme altitude, for example on the summit of Mount Everest. First, we need to refer to two simple equations governing pulmonary gas exchange. The first is the alveolar ventilation equation:
Vascular Innervation In The Respiratory Tract With Special Reference To Neuropeptides
Published in Geoffrey Burnstock, Susan G. Griffith, Nonadrenergic Innervation of Blood Vessels, 2019
Frank Sundler, Rolf Håkanson, Anders Luts, Rolf Uddman
The vascular supply of the respiratory system is of particular importance for two reasons. Firstly, the pulmonary gas exchange requires a well-developed vascular network and secondly, the air conditioning in the upper respiratory tract — the nasal mucosa in particular — depends upon the blood flow in the submucosal vascular bed. Not surprisingly, there is extensive literature on the autonomic innervation of blood vessels in the respiratory system. Techniques for the histochemical demonstration of acetylcholinesterase (AChE) enabled studies on the distribution of presumed cholinergic nerves in the respiratory tract in which AChE-positive nerve fibers were found to form dense plexuses around blood vessels.15 The Falck-Hillarp histofluorescence method for the localization of catecholamines6 revealed a rich supply of noradrenaline(NA)-containing nerve fibers around blood vessels in the respiratory tract, particularly in the upper portion, including the nasal mucosa.4,5,7-9 A functional characterization of the adrenergic and cholinergic pathways in the autonomic control of the airways was attempted decades before the morphological and anatomical characterization of the nerve supply was possible. Already in 1929 Undritz10 demonstrated an atropine-resistant vasodilatation in the nasal mucosa, a phenomenon which has since been encountered in many vascular beds.
Classifier for the functional state of the respiratory system via descriptors determined by using multimodal technology
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Sergey Alekseevich Filist, Riad Taha Al-kasasbeh, Olga Vladimirovna Shatalova, Altyn Amanzholovna Aikeyeva, Osama M. Al-Habahbeh, Mahdi Salman Alshamasin, Korenevskiy Nikolay Alekseevich, Mohammad Khrisat, Maksim Borisovich Myasnyankin, Maksim Ilyash
The least studied is the VLF range, which corresponds to slow waves with a period of 25 to 330 seconds. The difficulties in studying this range are that there is a rather significant zero harmonic (constant component of the signal) on the ECS spectrum, against which it is very difficult to distinguish the peaks of very low-frequency oscillations. The genesis of these waves, as well as on HF and LF, is explained by many hypotheses. One of them, described in (Sin et al. 2010), believes that the RR variability is based on the gas exchange mechanism. If this assumption is correct, then the intensity of pulmonary gas exchange, which reflects the rate of oxygen consumption, has a structure of slow waves of the second order and can be used as a marker of the FS of RS. In this case, the mechanism of optimal maintenance of CO2 tension in arterial blood is carried out by the central nervous system through feedbacks on variations in gas exchange parameters. But for the analysis of such indicators of external respiration, a long-term recording of a pneumogram and a registration of pulmonary gas exchange are necessary. It is very difficult to remove such parameters, since this requires special equipment that allows continuous
Human wharton-jelly mesenchymal stromal cells reversed apoptosis and prevented multi-organ damage in a newborn model of experimental asphyxia
Published in Journal of Obstetrics and Gynaecology, 2022
Bilge Kocabiyik, Erkan Gumus, Burcin Irem Abas, Ayse Anik, Ozge Cevik
Asphyxia is a significant problem, accounting for about a quarter of neonatal deaths worldwide. Perinatal asphyxia is the absence of blood flow or gas exchange to the foetus just before, during, or after birth. Perinatal asphyxia can cause profound systemic and neurological sequelae due to reduced blood flow and oxygen to a foetus or infant during the peripartum period (Rodríguez et al. 2020). When the placental or pulmonary gas exchange is compromised or completely interrupted, hypoxia or anoxia oxygen deficiency in vital organs accelerates anaerobic glycolysis due to decreased oxygenation in tissues and organs, resulting in lactic acidosis (Sugiura-Ogasawara et al. 2019). In neonatal hypoxic-ischaemic encephalopathy (HIE), neurological damage occurs along with these, and cerebral injury occurs (Hakobyan et al. 2019). Oxidative stress includes macromolecular oxidative damage, induces tissue protein denaturation, DNA damage, and lipid peroxidation, and interferes with the regular metabolic activity of the body, leading to the emergence and development of diseases, such as HIE (Zubrow et al. 2002, Eroglu et al. 2013). Primary biomarkers, such as cytokines, NSE, and GFAP in perinatal asphyxia are essential both in diagnosis and monitoring treatment. Responses of oxidative stress markers and cytokines in perinatal asphyxia may differ according to the treatments and are also used to detect organ damage.
Stabilization of Nrf2 leading to HO-1 activation protects against zinc oxide nanoparticles-induced endothelial cell death
Published in Nanotoxicology, 2021
Longbin Zhang, Liyong Zou, Xuejun Jiang, Shuqun Cheng, Jun Zhang, Xia Qin, Zhexue Qin, Chengzhi Chen, Zhen Zou
Endothelial cells form a one-cell-thick walled layer called the endothelium that lines the whole vascular system from the heart to the smallest capillary and regulates the passage of endogenous/exogenous materials and immune cells into and out of the bloodstream. These endothelial cells are recognized as major participants in inflammatory reactions (Pober and Sessa 2007). In particular, pulmonary microvascular endothelial cells and alveolar epithelial cells compose the blood-air barrier, which is the most important physiological structure for efficient pulmonary gas exchange. Disruption of the blood-air barrier is the fundamental pathophysiological characteristics of acute lung injury (Matthay, Ware, and Zimmerman 2012). Revealing the mechanisms underlying ZnONPs-induced endothelial cells damage will contribute to a better understanding of ZnONPs-induced lung injury and associated cardiovascular diseases (Wu et al. 2019). Therefore, we investigated whether ZnONPs induced the activation of Nrf2 in endothelial cells and mouse blood vessels and explored the antioxidative mechanisms activated in the context of ZnONPs treatment in vitro and in vivo.