scholarly journals Developing a “dry lab” activity using lower body negative pressure to teach physiology

2021 ◽  
Vol 45 (3) ◽  
pp. 445-453
Author(s):  
Nandu Goswami ◽  
Akanksha Singh ◽  
Kishore Kumar Deepak
Keyword(s):  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Research Question ◽  
New Delhi ◽  
Lower Body ◽  
Medical Sciences ◽  
Integrated Research ◽  
Confounding Variables ◽  
Teacher Surveys ◽  
Systems Physiology

In this paper we assessed how lower body negative pressure (LBNP) can be used to teach students the physiological effects of central hypovolemia in the absence of the LBNP and/or a medical monitor using a “dry lab” activity using LBNP data that have been previously collected. This activity was performed using published LBNP papers, with which students could explore LBNP as an important tool to study physiological responses to central hypovolemia as well as consider issues in performing an LBNP experiment and interpreting experimental results. The activity was performed at the All India Institute of Medical Sciences, New Delhi, with 31 graduate students and 4 teachers of physiology. Both students and teachers were provided with a set of questionnaires that inquired about aspects related to the structure of the activity and how this activity integrated research and knowledge, as well as aspects related to motivation of the students and teachers to perform the activity. Our results from student and teacher surveys suggest that a “dry lab” activity using LBNP to teach physiology can be an important tool to expose students to the basics of systems physiology as well as to provide useful insights into how research is performed. Providing insight into research includes formulating a research question and then designing (including taking into account confounding variables), implementing, conducting, and interpreting research studies. Finally, developing such an activity using LBNP can also serve as a basis for developing research capacities and interests of students even early in their medical studies.

Neurohormonal responses to oscillatory lower body negative pressure in healthy subjects

2021 ◽  
Author(s):  
Akanksha Singh ◽  
Shival Srivastav ◽  
Kavita Yadav ◽  
Dinu S. Chandran ◽  
Ashok Kumar Jaryal ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Healthy Subjects ◽  
Lower Body Negative Pressure ◽  
Lower Body

Bradykinin has no acute effect on the response of forearm blood flow to sympathetic stimulation in man

1990 ◽  
Vol 78 (4) ◽  
pp. 399-401 ◽  
Author(s):  
M. J. Cullen ◽  
J. R. Cockcroft ◽  
D. J. Webb
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Negative Pressure ◽  
Enzyme Inhibitor ◽  
Lower Body Negative Pressure ◽  
Acute Effect ◽  
Acute Administration ◽  
Lower Body ◽  
Resistance Vessels ◽  
Sympathetic Responses

1. Six healthy male subjects received 0.9% (w/v) NaCl (saline) followed by incremental doses of bradykinin (1, 3 and 10 pmol/min), via the left brachial artery. Blood flow and the response of blood flow to lower-body negative pressure were measured in both forearms during infusion of saline and each dose of bradykinin. 2. Bradykinin produced a moderate and dose-dependent increase in blood flow in the infused, but not the non-infused, forearm. Lower-body negative pressure produced an approximately 15–20% reduction in blood flow in both forearms, and this response was unaffected by local infusion of bradykinin. 3. Bradykinin, in contrast to angiotensin II, had no acute effect on peripheral sympathetic responses to lower-body negative pressure. We conclude that, in forearm resistance vessels in man, withdrawal of angiotensin II, rather than accumulation of bradykinin, is likely to account for the attenuation of peripheral sympathetic responses after acute administration of a converting-enzyme inhibitor.

The impact of menopausal status on cardiac responses to exercise training and lower body negative pressure

Maturitas ◽  
2017 ◽  
Vol 103 ◽  
pp. 91
Author(s):  
Amanda Q.X. Nio ◽  
Eric J. Stöhr ◽  
Samantha Rogers ◽  
Rachel Mynors-Wallis ◽  
Jane M. Black ◽  
...  
Keyword(s):  
Exercise Training ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Menopausal Status ◽  
Lower Body ◽  
Cardiac Responses ◽  
The Impact

VASOCONSTRICTOR RESPONSE TO LOWER BODY NEGATIVE PRESSURE DURING AUTONCMIC BLOCKADE

1986 ◽  
Vol 18 (supplement) ◽  
pp. S15
Author(s):  
H. L. Smith ◽  
D. L. Hudson ◽  
H. M. Graitzer ◽  
P. B. Raven
Keyword(s):  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Lower Body ◽  
Vasoconstrictor Response

Diaphragm afferent modulation of phrenic motor drive

1987 ◽  
Vol 62 (6) ◽  
pp. 2436-2441 ◽  
Author(s):  
D. L. Fryman ◽  
D. T. Frazier
Keyword(s):  
Negative Pressure ◽  
Phrenic Nerve ◽  
Lower Body Negative Pressure ◽  
Motor Drive ◽  
Lower Body ◽  
Inspiratory Time ◽  
Neural Drive ◽  
Dorsal Rhizotomy ◽  
Bilateral Vagotomy ◽  
Thiopental Sodium

Experiments were performed in eight lightly anesthetized thiopental sodium (Pentothal) cats to examine whether diaphragmatic afferents can significantly alter the neural drive to the diaphragm when the animal is exposed to lower body negative pressure. Moving-time-averaged diaphragmatic electromyograms (EMGma) were recorded and compared before and during exposure to lower body negative pressure in each of three consecutive conditions: C7 spinalization, bilateral vagotomy, and cervical dorsal rhizotomy. Application of lower body negative pressure in C7-spinalized animals resulted in a decrease in inspiratory time and peak diaphragmatic activity compared with control levels. After bilateral vagotomy, EMGma activity was prolonged with the application of lower body negative pressure. However, there was no increase in peak EMGma activity. After transection of the cervical dorsal roots subserving the phrenic nerve, the prolongation of diaphragmatic activity negative was eliminated. Therefore, we conclude that the significant increase in duration of inspiration in response to application of lower body negative pressure in the C7-spinalized, bilaterally vagotomized cat is mediated by phrenic nerve afferents.

Noise-Enhanced Heart Rate and Sympathetic Nerve Responses to Oscillatory Lower Body Negative Pressure in Humans

2001 ◽  
Vol 86 (2) ◽  
pp. 559-564 ◽  
Author(s):  
Ichiro Hidaka ◽  
Shin-Ichi Ando ◽  
Hideaki Shigematsu ◽  
Koji Sakai ◽  
Soko Setoguchi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Stochastic Resonance ◽  
Negative Pressure ◽  
Sympathetic Nerve ◽  
Carotid Sinus ◽  
Lower Body Negative Pressure ◽  
Arterial System ◽  
Lower Body ◽  
Cardiopulmonary Baroreceptors

By injecting noise into the carotid sinus baroreceptors, we previously showed that heart rate (HR) responses to weak oscillatory tilt were enhanced via a mechanism known as “stochastic resonance.” It remains unclear, however, whether the same responses would be observed when using oscillatory lower body negative pressure (LBNP), which would unload the cardiopulmonary baroreceptors with physically negligible effects on the arterial system. Also, the vasomotor sympathetic activity directly controlling peripheral resistance against hypotensive stimuli was not observed. We therefore investigated the effects of weak (0 to approximately −10 mmHg) oscillatory (0.03 Hz) LBNP on HR and muscle sympathetic nerve activity (MSNA) while adding incremental noise to the carotid sinus baroreceptors via a pneumatic neck chamber. The signal-to-noise ratio of HR, cardiac interbeat interval, and total MSNA were all significantly improved by increasing noise intensity, while there was no significant change in the arterial blood pressure in synchronized with the oscillatory LBNP. We conclude that the stochastic resonance, affecting both HR and MSNA, results from the interaction of noise with the signal in the brain stem, where the neuronal inputs from the arterial and cardiopulmonary baroreceptors first come together in the nucleus tractus solitarius. Also, these results indicate that the noise could induce functional improvement in human blood pressure regulatory system in overcoming given hypotensive stimuli.

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