Postgraduate School in Medical Physics, University of Bologna, Bologna, Italy;
School of Medicine, University of Bologna, Bologna, Italy;
Adv Physiol Educ. 2016 Sep;40(3):410-7. doi: 10.1152/advan.00096.2015.
This laboratory activity is designed to teach students how to measure forearm muscle blood flow (FBF) to describe the mechanisms of peripheral blood flow thermal regulation in healthy subjects. The cold pressor test (CPT) is the clinical procedure used in the experiment to induce arterial vasoconstriction. Strain-gauge plethysmography is applied on the patient's forearm to noninvasive monitor vasoconstriction effects on local blood perfusion and physiological parameters such as blood pressure (BP) and heart rate (HR). Patients with an altered peripheral vascular resistance (e.g., in hypertension) have different responses to the CPT from healthy subjects. To date, experimental evidence remains unexplained, as we do not know if the BP and HR increase is caused by a decrease in flow rate or an increase in peripheral vascular resistance during the test. To clarify this situation, we have to quantify the parameter we assume is being conditioned by the regulatory physiological intervention, i.e., peripheral vascular resistance. Peripheral vascular resistance quantification can be calculated as the ratio between muscle flow and mean arterial pressure. Students will learn how to apply the instrumental procedure to collect and analyze data before, during, and after the CPT and to describe the physiological responses of the peripheral vascular system to external stressors. They will also learn how to distinguish healthy from pathological responses on the basis of how sympathetic nervous system reactions influence the biomechanics of peripheral vessels.
本实验室活动旨在教导学生如何测量前臂肌肉血流（FBF），以描述健康受试者外周血流热调节的机制。冷加压试验（CPT）是实验中用于诱导动脉血管收缩的临床程序。应变计体积描记法应用于患者的前臂，以无创监测血管收缩对局部血液灌注和生理参数（如血压（BP）和心率（HR））的影响。外周血管阻力改变的患者（例如，高血压）对 CPT 的反应与健康受试者不同。迄今为止，实验证据仍未得到解释，因为我们不知道在测试过程中，BP 和 HR 的增加是由于流量减少还是外周血管阻力增加引起的。为了澄清这种情况，我们必须量化我们假设受调节生理干预条件的参数，即外周血管阻力。外周血管阻力的量化可以通过血流量与平均动脉压的比值来计算。学生将学习如何在 CPT 之前、期间和之后应用仪器程序来收集和分析数据，并描述外周血管系统对外部应激源的生理反应。他们还将学习如何根据交感神经系统反应如何影响外周血管的生物力学来区分健康和病理反应。
