Factors influencing orthostatic blood pressure regulation in healthy humans

动脉血压的正常节拍调节是至关重要的，并由许多集成机制精细地控制。动脉压力反射(一种血压调节反射)、血量、大脑和身体调节血管张力的能力、姿势摆动(站立时有节奏的肌肉收缩)、渗透压反射(饮用水引发的血管收缩)和情绪反应都有助于正常的血压控制。然而，它们在这个关键的生物系统中的调节和相互关系却知之甚少。血压调节的最大挑战之一是站立姿势(直立位)。当直立重力导致血液和液体聚集在身体的下部时，减少血液返回心脏，这必须得到补偿，以防止血压下降和生理功能受损。这在军事人员中尤其重要，因为立位应激，加上加剧的生理应激因素，如热应激或脱水，使心血管系统特别紧张。我研究的长期目标是阐明影响健康人正常立位血压控制的生理因素。拟议的探索计划将通过三个短期目标检验影响立位心血管控制的三种关键生理条件的效果：1)阐明腿部肌肉活动和立位心血管控制之间的关系；2)研究渗透压反射在心血管调节中的作用；3)确定情绪反应(血液/针头恐惧症)如何影响立位反应。我们将确定姿势摆动和血压控制之间的关系，确定某些摆动曲线是否对血压控制有更大的影响，并检查是否存在预示心血管不稳定的摆动“信号”。我们将测试水温是否影响渗透压反射之间的相互关系，以及饮用碳酸水导致的胃胀增加对渗透压反应的影响。我们还将研究注血创伤恐惧症低血压反应的机制。我们提出了一种新颖的综合实验方法，由一个拥有生理学、心脏病学、生物力学和姿势控制、可穿戴技术、统计学以及军事应用专业知识的多学科团队提出。我们将使用尖端方法进行评估，无论是在受控的实验室环境中，还是在现场使用可穿戴传感器的真实条件下。这些研究将提供关于健康人类血压调节机制的基础数据。这些数据对理解正常的人体生理学至关重要，并与军事社区和其他领域具有关键的相关性。

The normal beat-to-beat regulation of arterial blood pressure is vital, and exquisitely controlled by numerous integrated mechanisms. The arterial baroreflex (a blood pressure regulating reflex), volume of blood, ability to regulate blood vessel tone in the brain and body, postural sway (rhythmic muscle contraction when standing), osmopressor reflex (blood vessel constriction triggered by drinking water) and emotional responses all contribute to normal blood pressure control. However, their regulation and interrelationships in this critical biological system are poorly understood. One of the greatest challenges to blood pressure regulation is the standing posture (orthostasis). When upright gravity causes blood and fluid to pool in the lower parts of the body, reducing the return of blood to the heart, and this must be compensated to prevent blood pressure falling and impairing physiological function. This is of particular importance in military personnel where orthostatic stress, coupled with exacerbating physiological stressors such as thermal stress or dehydration, places particular strain on the cardiovascular system. The long-term goal of my research is to elucidate the physiological factors that influence normal orthostatic blood pressure control in healthy humans. The proposed Discovery program will examine the effects of three key physiological conditions that influence orthostatic cardiovascular control via three short-term objectives: 1) Elucidate the relationships between lower extremity muscle activity and orthostatic cardiovascular control; 2) Examine the role of the osmopressor reflex in cardiovascular regulation; and 3) Determine how emotional reactions (blood/needle phobia) influence orthostatic responses. We will determine the relationships between postural sway and blood pressure control, identify whether certain sway profiles have a greater effect on blood pressure control, and examine whether there is a sway "signature" that heralds the onset of cardiovascular instability. We will test whether water temperature influences the interrelationships between the osmopressor reflex, and the impact of increased stomach distension from drinking carbonated water on the osmopressor response. We will also study the mechanisms underlying hypotensive responses with blood-injection-injury phobia. We propose a novel, combined experimental approach from a multidisciplinary team with expertise in physiology, cardiology, biomechanics and postural control, wearable technology, statistics, as well as military applications. We will perform assessments using cutting-edge approaches, both in a controlled laboratory environment, as well as in real-world conditions in the field using wearable sensors. These studies will provide fundamental data on the mechanisms underlying blood pressure regulation in healthy humans. These data are critical to understanding of normal human physiology, and have key relevance to the military community and beyond.