Factors influencing orthostatic blood pressure regulation in healthy humans

正常的搏动对动脉血压的调节是至关重要的，并由许多综合机制精确地控制。动脉压力反射（一种血压调节反射）、血容量、调节大脑和身体血管张力的能力、体位摆动（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）。当直立的重力导致血液和液体聚集在身体的下部，减少血液返回心脏，这必须得到补偿，以防止血压下降和损害生理功能。这对军事人员尤其重要，因为他们的直立压力，加上加剧的生理压力，如热应激或脱水，给心血管系统带来了特别的压力。我研究的长期目标是阐明影响健康人正常体位血压控制的生理因素。提出的探索项目将通过三个短期目标来研究影响直立性心血管控制的三个关键生理条件的影响：1)阐明下肢肌肉活动与直立性心血管控制之间的关系；2)探讨渗透压反射在心血管调节中的作用；3)确定情绪反应（血/针恐惧症）如何影响直立反应。我们将确定体位摇摆与血压控制之间的关系，确定某些摇摆对血压控制是否有更大的影响，并检查是否存在预示心血管不稳定发作的摇摆“特征”。我们将测试水温是否影响渗透反射之间的相互关系，以及饮用碳酸水增加的胃胀对渗透反应的影响。我们还将研究与血液注射损伤恐惧症相关的降压反应机制。我们提出了一种新颖的，结合实验方法，来自多学科团队，具有生理学，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方面的专业知识。我们将使用尖端的方法进行评估，无论是在受控的实验室环境中，还是在使用可穿戴传感器的实际条件下。这些研究将为健康人类血压调节机制提供基础数据。这些数据对于理解正常的人体生理学是至关重要的，并且对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.