Mechanoreceptor afferent activity compared with receptor field dimensions and pressure changes in feline urinary bladder

1992 ◽  
Vol 70 (11) ◽  
pp. 1457-1467 ◽  
Author(s):  
John W. Downie ◽  
J. Andrew Armour
Keyword(s):  
Contractile Activity ◽  
Bladder Wall ◽  
Afferent Activity ◽  
Intravesical Pressure ◽  
Receptor Field ◽  
Precise Relationship ◽  
Pressure Changes ◽  
The Relationship ◽  
Simple Fashion ◽  
Pressure Receptor

The relationship between vesical mechanoreceptor field dimensions and afferent nerve activity recorded in pelvic plexus nerve filaments was examined in chloralose-anesthetized cats. Orthogonal receptor field dimensions were monitored with piezoelectric ultrasonic crystals. Reflexly generated bladder contractile activity made measurements difficult, therefore data were collected from cats subjected to actual sacral rhizotomy. Afferent activity was episodic and was initiated at different pressure and receptor field dimension thresholds. Maximum afferent activity did not correlate with maximum volume or pressure. Furthermore, activity was not linearly related to intravesical pressure, receptor field dimensions, or calculated wall tension. Pressure–length hysteresis of the receptor fields occurred. The responses of identified afferent units and their associated receptor field dimensions to brief contractions elicited by the ganglion stimulant 1,1-dimethyl-4-phenylpiperazinium iodide (2.5–20 μg i.a.), studied under constant volume or constant pressure conditions, are compatible with bladder mechanoreceptors behaving as tension receptors. Because activity generated by bladder mechanoreceptors did not correlate in a simple fashion with intravesical pressure or receptor field dimensions, it is concluded that such receptors are influenced by the viscoelastic properties of the bladder wall. Furthermore, as a result of the heterogeneity of the bladder wall, receptor field tension appears to offer a more precise relationship with the activity of bladder wall mechanoreceptors than does intravesical pressure.Key words: bladder distension, intravesical pressure, sacral rhizotomy, viscoelasticity.

Mechanoreceptors sensitive to flow at the gastroduodenal junction of the cat

1993 ◽  
Vol 265 (2) ◽  
pp. G310-G313 ◽  
Author(s):  
C. H. Malbert ◽  
L. M. Leitner
Keyword(s):  
Flow Rate ◽  
Back Pressure ◽  
Intraluminal Pressure ◽  
Afferent Activity ◽  
Pentobarbital Sodium ◽  
Proximal Duodenum ◽  
Vagal Afferent ◽  
Pressure Changes ◽  
The Relationship

Vagal afferent activity was recorded from the cervical vagus simultaneously with intraluminal pressure and flow rate at the proximal duodenum, in cats anesthetized with pentobarbital sodium. Thirty-seven mechanoreceptors that adapted slowly to maintained pressure changes were found to be sensitive to the flow of saline through the pylorus. The passage of liquid was associated with an increase of pressure equal to one-tenth of that necessary to trigger a response of the receptors during the distension of a small balloon. The frequency of discharge was increased by the passage of liquid for positive back pressures < or = 1.5 kPa but not when back pressure was negative. The relationship between the discharge of the receptor and the flow rate was complex and showed an hysteresis. We conclude that there exist slowly adapting mechanoreceptors sensitive to distension of the duodenum that can also sense the passage of liquid.

Depressive Disorder in Primary Care

1987 ◽  
Vol 150 (6) ◽  
pp. 737-751 ◽  
Author(s):  
C. V. R. Blacker ◽  
A. W. Clare
Keyword(s):  
Primary Care ◽  
Depressive Symptoms ◽  
Depressive Disorders ◽  
Psychiatric Morbidity ◽  
Depressive Illness ◽  
Psychiatric Disturbance ◽  
Collaborative Studies ◽  
Effect Of Treatment ◽  
Precise Relationship ◽  
The Relationship

Since the pioneering study of psychiatric morbidity in primary care by Shepherdet alin 1966, it has become increasingly apparent that a substantial proportion (between 20% and 25%) of patients consulting their GP are suffering from some form of psychiatric disturbance (Goldberg & Blackwell, 1970; Hoeperet al,1979). The composition of this psychiatric morbidity has been shown to be almost wholly affective in nature and largely mild in degree. In their important review Jenkins & Shepherd (1983) recently summarised the now extensive findings relating to overall minor psychiatric morbidity in primary care. However, recent collaborative studies between psychiatrists and GPs have identified that within this dilute pool of minor disorders, lurks a significant but poorly served population of patients suffering from depressive disorders which are by no means minor in degree. A number of crucial issues regarding this depression in primary care emerge which the present paper aims to review. In particular, how common is it, and how severe? How does it present and what, if any, are its special characteristics? What is the precise relationship between depressive symptoms and depressive illness presenting to the GP and what is the relationship between physical illness and depression? And finally, what is the course and outcome of depression in this setting and what are the indications for and effect of treatment?

scholarly journals Analysis of Stress and Strain to Determine the Pressure Changes in Tight-Fitting Garment

2020 ◽  
Vol 20 (1) ◽  
pp. 49-55
Author(s):  
Nareerut Jariyapunya ◽  
Blažena Musilová
Keyword(s):  
Mechanical Properties ◽  
Mathematical Models ◽  
Initial Phase ◽  
Circumferential Stress ◽  
The Body ◽  
Stress And Strain ◽  
Laplace’S Law ◽  
Pressure Changes ◽  
The Relationship ◽  
Laplace's Law

AbstractBased on the mechanical properties of stretch fabrics and Laplace’s law, the mathematical models have been developed enabling one to determine the values of the relationship between the fabric strain and the circumferential stress depending on pressure and diameter of the body. The results obtained refer to the values of the parameters assessed for the initial phase of their exploitation, which allow us to preliminarily predict the values of these parameters.

scholarly journals Modulation of Bladder Wall Micromotions Alters Intravesical Pressure Activity in the Isolated Bladder

2019 ◽  
Vol 9 ◽  
Author(s):  
Basu Chakrabarty ◽  
Dominika A. Bijos ◽  
Bahareh Vahabi ◽  
Francesco Clavica ◽  
Anthony J. Kanai ◽  
...  
Keyword(s):  
Bladder Wall ◽  
Intravesical Pressure

Measurement of alveolar gas volume by ambient pressure changes in isolated lungs

1988 ◽  
Vol 65 (3) ◽  
pp. 1281-1285
Author(s):  
R. R. Martin ◽  
R. Peslin ◽  
C. Duvivier ◽  
C. Gallina
Keyword(s):  
Water Vapor ◽  
Ambient Pressure ◽  
Water Vapor Pressure ◽  
Volumetric Method ◽  
The Body ◽  
Highly Correlated ◽  
Isolated Lungs ◽  
Pressure Changes ◽  
Gas Volume ◽  
The Relationship

Alveolar gas volume (AGV) may be measured in humans (Peslin et al., J. Appl. Physiol. 62: 359-363, 1987) by applying very slow sinusoidal variations of ambient pressure (delta Pam) around the body and studying the relationship between delta Pam and the resulting gas displacement at the mouth (delta Vaw): AGVapc = (PB.delta Vaw)/(delta Pam.cos phi), where AGVapc is AGV measured by ambient pressure changes, PB is barometric minus alveolar water vapor pressure, and phi is the phase angle between Pam and Vaw. The applicability of this method to excised lungs at various transpulmonary pressures was assessed in six rabbit lungs and three dog lobes by reference to AGV measurements by He dilution (AGVdil) and by a volumetric method (AGVvol). Except in one instance, AGVapc did not change significantly when the frequency of delta Pam was varied from 0.02 to 0.2 Hz. AGVapc was highly correlated (P less than 0.001) to both AGVdil and AGVvol. It did not differ significantly from AGVdil (81.4 +/- 50.6 vs. 80.2 +/- 44.2 ml) and was only marginally higher than AGVvol (64.6 +/- 26.9 vs. 62.4 +/- 24.4 ml, P less than 0.05). We conclude that the method usually provides accurate results in excised lung preparations. Its main advantages are that it does not require manipulating the lung or changing its volume and that the measurement takes less than 1 min.

Utility of gas inlet pressure monitoring in extracorporeal membrane oxygenation

2020 ◽  
pp. 039139882096212
Author(s):  
Yuki Nakamura ◽  
Takafumi Nakakita ◽  
Kazuhiko Yamamoto ◽  
Aki Kamada ◽  
Shinichi Iguchi ◽  
...  
Keyword(s):  
Gas Flow ◽  
Sodium Dodecyl ◽  
Significant Negative Correlation ◽  
Solution Concentration ◽  
Flow Path ◽  
Inlet Pressure ◽  
Plasma Leakage ◽  
Pressure Changes ◽  
The Relationship ◽  
Reduced Surface

Purpose: Purpose: Condensation that clogs the hollow fibers of the oxygenation and accumulation of plasma leaks reduces oxygenated lung capacity. In this study, artificial We evaluated whether monitoring changes in lung gas inlet pressure was a way to predict these complications. Methods: Changes in gas inlet pressure and oxygenation capacity of three different prostheses (BIOCUBE6000, EXCELUNG PRIME, and Capiox-LX) Evaluated the relationship. When simulating plasma leakage using BIOCUBE6000, sodium dodecyl sulfate (SDS) (1%, 0.1%, A solution of 0.01%, and RO water) reduced surface tension. During 120 minutes of circulation, changes in gas inlet pressure and leakage from the membrane into the gas flow path The amount of fluid was measured. Results: There was a significant negative correlation between the gas inlet pressure changes and the oxygenation capacity of all three oxygenators (BIOCUBE6000: R2 = 0.957, EXCELUNG PRIME: R2 = 0.946, Capiox-LX: R2 = 0.878). After 120 min of SDS solution circulation using the BIOCUBE6000, both the gas inlet pressure and the volume of fluid leaking from the membrane into the gas flow path increased in proportion to the SDS solution concentration: RO water (0.56 ± 0.11 mmHg and 16.67 mL ± 0.94 mL), 0.01% SDS (0.98 ± 0.11 mmHg and 23.3 ± 0.47 mL,) 0.1% SDS (1.64 ± 0.21 mmHg and 29.0 ± 1.63 mL), and 1%SDS (14.3 ± 0.27 mmHg and 36.7 ± 0.47 mL) (n = 3). Conclusion: This study confirmed that monitoring the gas inlet pressure changes of an oxygenator during ECMO is clinically useful.

scholarly journals Features of glossopharyngeal breathing in breath-hold divers

2006 ◽  
Vol 101 (3) ◽  
pp. 799-801 ◽  
Author(s):  
Leigh M. Seccombe ◽  
Peter G. Rogers ◽  
Nghi Mai ◽  
Chris K. Wong ◽  
Leonard Kritharides ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Total Lung Capacity ◽  
Breath Hold ◽  
Lung Capacity ◽  
Diving Depth ◽  
Highly Correlated ◽  
Pressure Changes ◽  
Air Compression ◽  
The Relationship ◽  
Measured Volume

One technique employed by competitive breath-hold divers to increase diving depth is to hyperinflate the lungs with glossopharyngeal breathing (GPB). Our aim was to assess the relationship between measured volume and pressure changes due to GPB. Seven healthy male breath-hold divers, age 33 ( 8 ) [mean (SD)] years were recruited. Subjects performed baseline body plethysmography (TLCPRE). Plethysmography and mouth relaxation pressure were recorded immediately following a maximal GPB maneuver at total lung capacity (TLC) (TLCGPB) and within 5 min after the final GPB maneuver (TLCPOST). Mean TLC increased from TLCPRE to TLCGPB by 1.95 (0.66) liters and vital capacity (VC) by 1.92 (0.56) liters ( P < 0.0001), with no change in residual volume. There was an increase in TLCPOST compared with TLCPRE of 0.16 liters (0.14) ( P < 0.02). Mean mouth relaxation pressure at TLCGPB was 65 (19) cmH2O and was highly correlated with the percent increase in TLC ( R = 0.96). Breath-hold divers achieve substantial increases in measured lung volumes using GPB primarily from increasing VC. Approximately one-third of the additional air was accommodated by air compression.

Observations on Intravesical Pressure Changes During Micturition

1960 ◽  
Vol 84 (1) ◽  
pp. 106-110 ◽  
Author(s):  
John J. Murphy ◽  
Harry W. Schoenberg
Keyword(s):  
Intravesical Pressure ◽  
Pressure Changes

The Effect of Abscission of Insulation Lining of Electromagnetic Flowmeter on Output Signal

2012 ◽  
Vol 226-228 ◽  
pp. 1910-1915
Author(s):  
Song Gao ◽  
Bin Li ◽  
Shi Yi Yin ◽  
Xue Jing Li
Keyword(s):  
Output Signal ◽  
Short Circuit ◽  
Electromagnetic Flowmeter ◽  
Fluid Temperature ◽  
Flow Meter ◽  
Electromagnetic Flow ◽  
Electromagnetic Flow Meter ◽  
Pressure Changes ◽  
Relationship Of ◽  
The Relationship

In pipe of electromagnetic flowmeter must be installed internal insulation lining to prevent the electromagnetic flowmeter signal is short circuit by metal pipe. However, in the process of using the electromagnetic flow meter, insulation lining is easy to fall off because of the fluid temperature and pressure changes, thus lead to the output signal of the electromagnetic flowmeter is changed. The effect of electromagnetic flowmeter insulation lining fall off to the output signal is analyzed by the theory of electromagnetic flow meters weight function. Get the relationship of the output signal and the insulation lining drop area and position. The paper provides a theoretical analysis method for the effect abscission of insulation lining of electromagnetic flow meter on output signal.

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