scholarly journals Studies on temperature regulation. I. The Pulmonata and Oligochaeta

1944 ◽  
Vol 132 (868) ◽  
pp. 239-252 ◽  
Keyword(s):  
Body Temperature ◽  
Temperature Regulation ◽  
Helix Pomatia ◽  
Ground Level ◽  
The Body ◽  
Saturation Point ◽  
Dry Air ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Binding Power

The slug, Arion ater , at all times, and the snail, Helix pomatia , when fully extended, maintain a body temperature well below that of the surrounding air unless it is fully saturated, and slightly, if at all, above that of the wet-bulb thermometer. By withdrawal into the microclimate of the shell the snail can appreciably reduce loss of water by evaporation; and in such circumstances its body temperature tallies more nearly with that of the surrounding atmosphere. After the formation of the epiphragm the body temperature of H. pomatia is identical with that of the atmosphere outside and varies accordingly. Since the slime of the slug loses water in air unless the R. H. is very near saturation point the water­-binding power of the mucus is not an effective check to loss of water by evaporation. The body temperature of an earthworm after relatively short periods of exposure to fairly dry air diverges increasingly from the wet-bulb reading. This appears to be due to rapid desicca­tion of the surface. Since the upper thermal death-point of the earthworm is relatively low, this means that earthworms are not adapted to long survival at ground level in sunlight. To this extent their equipment for maintaining body temperature below the danger point accords both with their habits, and with what views may plausibly be entertained about their ancestry.

scholarly journals The Temperature and Humidity Relations of the cockroach

1936 ◽  
Vol 13 (1) ◽  
pp. 28-34
Author(s):  
DONALD L. GUNN ◽  
F. B. NOTLEY
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Moist Air ◽  
Dry Air ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Ecological Importance

1. The thermal death-points of three species of cockroaches in dry and in moist air have been determined for 1-day and 1-hour exposures. 2. Moist air is more favourable than dry in the longer exposures, because in dry air death occurs from desiccation when the temperature itself is not fatal. 3. Dry air is more favourable than moist in the shorter exposures, owing to the fact that the evaporation of water lowers the body temperature. 4. Bearing in mind the thermotactic behaviour of these animals, these observations would seem to have little ecological importance.

Observations on the Thermal Death Points of the Blow-fly at different relative Humidities

1928 ◽  
Vol 18 (4) ◽  
pp. 397-403 ◽  
Author(s):  
Mary V. F. Beattie
Keyword(s):  
Relative Humidity ◽  
Blow Fly ◽  
Dry Air ◽  
Optimum Point ◽  
Thermal Death ◽  
Thermal Death Point

In summarising, the following points are to be noted:—1. The thermal death point of the blow-fly was definitely influenced by the factor of humidity.2. Saturated and dry air had the effect of lowering the thermal death point.3. Relative humidities from 60 per cent. to 80 per cent. were more favourable, while relative humidity of 70 per cent. actually was found to be an optimum point.4. From the weighings it may be concluded that death in saturated air was due to the inability of the flies to regulate their heat by evaporation.

scholarly journals The Influence of Starvation on the Thermal Death-Point on Insects

1934 ◽  
Vol 11 (1) ◽  
pp. 48-53
Author(s):  
MELLANBY KENNETH
Keyword(s):  
High Temperatures ◽  
Moist Air ◽  
Dry Air ◽  
Pediculus Humanus ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Food Reserves

Experiments are described in which newly hatched larval lice (Pediculus humanus corporis) and adult C. fatigans were exposed to high temperatures. The humidity was controlled, and the exposures lasted for either 1 or 24 hours. Larval lice, whether fed or unfed, withstood 46.5° C. for 1 hour, while the Culex were much less resistant--they only withstood a temperature of 39° C. The humidity of the air did not affect these results. When exposed for 24 hours, larval lice which had fed withstood 38° C. in moist air. They only withstood 33° C. in dry air, as they were killed by desiccation at higher temperatures. Mosquitoes (C. fatigans) which had gorged gave similar results. They survived 37° C. for 24 hours in moist air, and only 32° C. in dry. Unfed lice or mosquitoes behaved differently, as they could not withstand such high temperatures for periods of 24 hours. This was because they had small food reserves, and at high temperatures their rate of metabolism was so increased that they died of starvation.

scholarly journals Formation of the “setting” level of body temperature regulation during endotoxin fever

2020 ◽  
Vol 17 (1) ◽  
pp. 28-37
Author(s):  
F. I. Vismont ◽  
A. F. Vismont
Keyword(s):  
Body Temperature ◽  
Blood Plasma ◽  
Temperature Regulation ◽  
Brain Temperature ◽  
The Body ◽  
Body Temperature Regulation ◽  
Norepinephrine Turnover ◽  
Arginine Hydrochloride ◽  
Biochemical Research ◽  
The Brain

The experiments on rats and rabbits using modern physiological, biochemical research methods and the pharmacological approach established that in the body, the action of bacterial endotoxin, accompanied by fever, leads to a significant decrease in blood plasma and in CSF of the arginine content. In rabbits after 30 min intravenous administration of carbon-labeled arginine hydrochloride (25 μCi/kg) at the endotoxin fever peak (after the 60 min injection of endotoxine E. coli), the radioactivity level in the blood plasma decreases and significantly increases in the cerebrospinal fluid and the hypothalamus tissue. It was revealed that although the content and speed of norepinephrine turnover in the hypothalamus after the introduction of L-arginine hydrochloride (100 μg) into the ventricles of the rats does not change in comparison with control animals, however, the chemoreactive properties of the thermoregulatory structures of the brain have changed, which manifests itself in the change in the expression and duration of thermoregulatory effects of the central action of norepinephrine and acetylcholine. It was established that the administration of L-arginine hydrochloride into the brain ventricles at a dose of 100 μg per animal or in the blood flow at a dose of 20 mg/kg caused the pronounced antipyretic effect. It was found that L-arginine hydrochloride (100 μg), after it has been introduced into the ventricles of the brain, increases the impulse activity of heat-sensitive neurons of the medial preoptic region of the anterior hypothalamus in rabbits due to a brain temperature growth when the animal’s body is overheated. Apparently, CSF arginine can be considered as an important factor in the changes in the excitability thresholds of cold and heat-sensitive neurons in the hypothalamus and in the formation of the “setpoint” of body temperature regulation during endotoxin fever.

Temperature regulation in the Black Vulture

1982 ◽  
Vol 60 (4) ◽  
pp. 491-494 ◽  
Author(s):  
Jacques Larochelle ◽  
Jeffrey Delson ◽  
Knut Schmidt-Nielsen
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Head And Neck ◽  
Air Temperature ◽  
Temperature Regulation ◽  
Heat Dissipation ◽  
The Body ◽  
Laboratory Conditions ◽  
Black Vulture

Metabolic rate, body temperature, and heat dissipating mechanisms of the Black Vulture were studied under laboratory conditions. The metabolic rate (6.5 W) was close to the predicted one. The body temperature showed considerable variations with air temperature, ranging from 37.7 °C at 15 °C to 42.9 °C at 45 °C. The area of featherless skin on the head and neck changed with the body temperature, thus indicating a role in heat dissipation, and we conclude that these featherless skin areas can be adjusted according to the need for temperature regulation.

Cyanate and temperature regulation in anephric rabbits

1985 ◽  
Vol 249 (1) ◽  
pp. F69-F73
Author(s):  
S. M. Eiger ◽  
M. J. Kluger
Keyword(s):  
Plasma Concentration ◽  
Body Temperature ◽  
Temperature Regulation ◽  
Plasma Concentrations ◽  
The Body ◽  
Acute Response ◽  
Circulating Levels ◽  
Sodium Cyanate ◽  
Lowered Body

Knochel and Seldin proposed that the lowered body temperature observed during uremia was caused by an elevation in the circulating levels of cyanate. To test this hypothesis, normal rabbits were infused with varying concentrations of sodium cyanate. Infusion of pharmacological doses of cyanate (plasma concentration rose to 1,080 +/- 70 microM, n = 5) resulted in reductions in body temperature similar to that found during uremia; however, when normal rabbits were nephrectomized the plasma cyanate concentration only rose from 3.7 +/- 1.6 to 18 +/- 1.8 microM (n = 8) by 1-day postnephrectomy (body temperature fell 0.33 +/- 0.1 degrees C, n = 6). Plasma cyanate concentration did not rise further on days 2 and 3 postnephrectomy, despite a continued fall in body temperature. Infusion of cyanate in control rabbits to plasma concentrations attained 1-3 days postnephrectomy did not result in a fall in body temperature. Based on the failure of pathophysiological concentrations of cyanate to cause a reduction in the body temperature of normal rabbits, we conclude that cyanate is not responsible for the lowered body temperature associated with the acute response to uremia.

The Influence of Atmospheric Humidity on the Thermal Death Point of a Number of Insects

1932 ◽  
Vol 9 (2) ◽  
pp. 222-231
Author(s):  
MELLANBY KENNETH
Keyword(s):  
High Temperature ◽  
Low Temperatures ◽  
Causes Of Death ◽  
Moist Air ◽  
Atmospheric Humidity ◽  
Dry Air ◽  
Hot Air ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Large Meal

An account is given of a technique suitable for exposing small insects to high temperature and air of controlled humidity. Data of survival points obtained from a number of species are given, for 1-hour and 24-hour experiments. In the 1-hour experiments, the humidity of the air had no effect on the death point, except in the case of large meal-worms, which died at 1° C. higher in dry air than in moist. The temperature which any species can stand for 1 hour is sharply defined, but there is a range of 7° C. between the species of insects worked with. In 24-hour experiments, in moist air, all the species died between 36 and 39.5° C. Their death was presumably caused by the heat. In dry air, those insects not able to conserve their water died at low temperatures--22° C. in the case of flea larvae: this was attributed to desiccation. There seem to be two main causes of death of insects when they are killed at high temperatures: (1) When the temperature is over 40° C., they die from the effects of the heat. (2) Below 36° C. all the insects experimented with were able to survive at least 24 hours in moist air, but in dry air insects unable to conserve their water may die of desiccation. In hot air, over 40° C., certain large insects are better able to survive in dry air, as they keep their bodies cool by evaporating water. I am grateful to Mr H. S. Leeson for the supply of X. cheopis, and to Dr R. P. Hobson for the Lucilia adults. And I am indebted to Dr P. A. Buxton and Dr V. B. Wigglesworth, who made many helpful suggestions when the work was in progress and who read through the typescript.

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