scholarly journals The effects of subcutaneous fat and of previous exposure to cold on the body temperature, peripheral blood flow and metabolic rate of men in cold water

1960 ◽  
Vol 153 (1) ◽  
pp. 166-178 ◽  
Author(s):  
W. R. Keatinge
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Peripheral Blood ◽  
Cold Water ◽  
Subcutaneous Fat ◽  
The Body ◽  
Peripheral Blood Flow ◽  
Previous Exposure ◽  
Exposure To Cold

Fluctuation of peripheral blood flow in subjects with circulatory impairment

1961 ◽  
Vol 16 (1) ◽  
pp. 61-63 ◽  
Author(s):  
Ernst K. Franke
Keyword(s):  
Thermal Conductivity ◽  
Blood Flow ◽  
Peripheral Blood ◽  
The Body ◽  
Cardiac Patients ◽  
Peripheral Blood Flow ◽  
Mutual Distance ◽  
Main Function ◽  
Lower Amplitude ◽  
Normal Controls

Fluctuations of the capillary blood flow in the skin of the hands of cardiac patients were compared with those of normal controls. In normal subjects the peripheral blood flow undergoes spontaneous, rhythmic fluctuations of a period of 30–60 seconds, whose main function is the regulation of the body temperature. These fluctuations were recorded by means of a probe that was sensitive to the effective thermal conductivity of the skin, which is proportional to the blood flow in its capillaries. The essential elements of the probe are two wires (constantan, 0.2 mm) of 1-cm length that are in contact with the skin at a mutual distance of 0.5 cm. One of the wires is heated by alternating current. The temperature difference that therefore develops between these wires is proportional to the thermal conductivity of the skin. It is recorded by means of thermocouples in contact with the wires. It was found that the cardiac patients had, on the average, a substantially lower amplitude of fluctuations than the normal controls. It is assumed that this may be attributed to anatomical changes of the arteriolar walls, which cause increased rigidity. Submitted on August 10, 1959

Effects of pentobarbital on temperature and heart rate of rats subjected to cold

1962 ◽  
Vol 203 (4) ◽  
pp. 758-761 ◽  
Author(s):  
C. L. Gemmill ◽  
K. M. Browning
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Standard Dose ◽  
The Body ◽  
Sodium Pentobarbital ◽  
Previous Exposure ◽  
Exposure To Cold ◽  
Before And After

A study at 5 C was made of body temperature and heart rate after a standard dose of sodium pentobarbital in normal, thyroidectomized, and hypermetabolic rats before and after subjection to 5 C for 46 hr. It was found that after subjection to cold in the normal rats, the body temperature and heart rate in some animals had more ability to recover after the barbiturate than in rats without previous exposure to cold. There was no ability to recover in the thyroidectomized animals either before or after subjection to cold. Most of the normal and thyroidectomized rats either with or without previous exposure to cold given sodium 3,3',5-l-triiodothyronine (T-3) had recoveries after the barbiturate. Some rats given T-3 and subjected to cold had a primary fall in temperature and heart rate that was followed by recovery and then a secondary fall.

Afterdrop of body temperature during rewarming: an alternative explanation

1986 ◽  
Vol 60 (2) ◽  
pp. 385-390 ◽  
Author(s):  
P. Webb
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Peripheral Blood ◽  
Alternative Explanation ◽  
Mild Hypothermia ◽  
Physical Models ◽  
Peripheral Blood Flow ◽  
Body Temperatures ◽  
Cold Blood ◽  
Deep Body

Afterdrop, the continued fall of deep body temperatures during rewarming after hypothermia, is thought to endanger the heart by further cooling from cold blood presumed to be returning from the periphery. However, afterdrop is not always observed, depending on the circumstances. To explore this phenomenon, mild hypothermia was induced quantitatively with a suit calorimeter, using several patterns of cooling and rewarming. When cooling was rapid and followed immediately by rewarming, there were typical afterdrops in the temperatures measured in the rectum, auditory canal, and esophagus. However, when rewarming was delayed, or when cooling had been slow and prolonged, afterdrop was not seen. Afterdrops were then observed in two physical models that had no circulation: a bag of gelatin and a leg of beef. Central layers continued to give up heat as long as the surrounding layer was cooler. These results, together with recent findings by others that peripheral blood flow is low until afterdrop is complete, make this circulatory explanation of afterdrop improbable. Alternatively, afterdrop can be explained by the way heat moves through a mass of tissue.

Peripheral blood flow changes in response to postexercise cold water immersion

2016 ◽  
Vol 38 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Hui C. Choo ◽  
Kazunori Nosaka ◽  
Jeremiah J. Peiffer ◽  
Mohammed Ihsan ◽  
Chow C. Yeo ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Blood ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Peripheral Blood Flow ◽  
Flow Changes

Biophysical constraints on the thermal ecology of dinosaurs

Paleobiology ◽  
1999 ◽  
Vol 25 (3) ◽  
pp. 341-368 ◽  
Author(s):  
Michael P. O'Connor ◽  
Peter Dodson
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Metabolic Rate ◽  
The Body ◽  
Behavioral Thermoregulation ◽  
Seasonal Adjustment ◽  
List Type ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Precise Control

A physical, model-based approach to body temperatures in dinosaurs allows us to predict what ranges of body temperatures and what thermoregulatory strategies were available to those dinosaurs. We argue that 1.The huge range of body sizes in the dinosaurs likely resulted in very different thermal problems and strategies for animals at either end of this size continuum.2.Body temperatures of the smallest adult dinosaurs and of hatchlings and small juveniles would have been largely insensitive to metabolic rates in the absence of insulation. The smallest animals in which metabolic heating resulted in predicted body temperatures ≥ 2°C above operative temperatures (Te) weigh 10 kg. Body temperature would respond rapidly enough to changes in Te to make behavioral thermoregulation possible.3.Body temperatures of large dinosaurs (>1000 kg) likely were sensitive to both metabolic rate and the delivery of heat to the body surface by blood flow. Our model suggests that they could adjust body temperature by adjusting metabolic rate and blood flow. Behavioral thermoregulation by changing microhabitat selection would likely have been of limited utility because body temperatures would have responded only slowly to changes in Te.4.Endothermic metabolic rates may have put large dinosaurs at risk for overheating unless they had adaptations to shed the heat as necessary. This would have been particularly true for dinosaurs with masses > 10,000 kg, but simulations suggest that for animals as small as 1000 kg in the Tropics and in temperate latitudes during the summer, steady-state body temperatures would have exceeded 40°C. Slow response of body temperatures to changes in Te suggests that use of day-night thermal differences would have buffered dinosaurs from diel warming but would not have lowered body temperatures sufficiently for animals experiencing high mean daily Te.5.Endothermic metabolism and metabolic heating might have been useful for intermediate and large-sized (100–3000 kg) dinosaurs but often in situations that demanded marked seasonal adjustment of metabolic rates and/or precise control of metabolism (and heat-loss mechanisms) as typically seen in endotherms.

scholarly journals Effects of haemorrhage on the distribution of the peripheral blood flow in the rabbit

1967 ◽  
Vol 192 (2) ◽  
pp. 561-574 ◽  
Author(s):  
J. P. Chalmers ◽  
P. I. Korner ◽  
S. W. White
Keyword(s):  
Blood Flow ◽  
Peripheral Blood ◽  
Peripheral Blood Flow
Sign in / Sign up

Export Citation Format

Share Document