Cardiovascular and sweating responses to water ingestion during dehydration

The experiments reported are concerned with cardiovascular and sudomotor events preceding, accompanying, and following ingestion of water by five dehydrating subjects 8.75 hr after entrance into a heat chamber (43.3 C DB, 29 C WB). Certain skin areas such as the cheek showed increases in evaporative heat loss before subjects came in contact with water. This reflex could be initiated by saline ingestion but the degree of skin and oral temperature changes appeared to depend on tonicity of fluid ingested. The gustatory reflex was not thought to be the initiating agent for sudomotor responses. Increases in cutaneous blood flow appeared to begin almost as promptly as sweating responses but took considerably longer to develop. Ingestion of saline, though initiating a sweating response, did not alter heart rate, blood pressure, or cutaneous blood flow. It is suggested that fluid ingestion, regardless of tonicity, triggers reflex sweating over the body surface. Intensity and duration of this sudomotor response, as well as initiation of cardiovascular changes, apparently depend on tonicity of ingested fluid. cutaneous blood flow; skin temperature; regional sweating Submitted on November 27, 1964

Download Full-text

Influence of blood flow on cutaneous permeability to inert gas

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.4.1167 ◽

1984 ◽

Vol 57 (4) ◽

pp. 1167-1172 ◽

Cited By ~ 5

Author(s):

Y. C. Lin ◽

N. Kakitsuba ◽

D. K. Watanabe ◽

G. W. Mack

Keyword(s):

Blood Flow ◽

Ambient Temperature ◽

Gas Diffusion ◽

The Body ◽

Inert Gases ◽

Inert Gas ◽

Human Hand ◽

Cutaneous Blood Flow ◽

Diffusion Distance ◽

Cutaneous Blood

A thermally regulated Plexiglas chamber was designed for investigation of transcutaneous diffusion of N2 and helium (He) in the human hand. Influence of cutaneous blood flow in this process was studied simultaneously with gas diffusion measurements. Changes in cutaneous blood flow (Q, in ml X min-1 X 100 ml tissue-1) were effected by altering ambient temperature (T) from 20 to 40 degrees C (Q = 0.08 X 100.07T). We found that the rate of inert gas diffusion through human skin, expressed as conductance (G, in ml STPD X h-1 X m-2 X atm-1), increases exponentially as a function of blood flow, and was indistinguishable between He and N2 (G = 21.19 X 100.0124Q). The permeability, diffusion coefficient per unit diffusion distance (D/h, in cm/h), also rose exponentially as a function of blood flow. But permeability for He (D/h = 0.1748 X 100.0203Q) was greater than that for N2 (D/h = 0.1678 X 100.0114Q). As cutaneous blood flow rises, because of increased temperature, the apparent diffusion distance falls linearly for both N2 and He. The change is more prominent for He than for N2 diffusion. Estimated replacement time for the body stores of N2 by transcutaneous diffusion alone was shortened from 26.8 h at 31 degrees C to 15.1 h at 37 degrees C. It is suggested from this study that beneficial results may be derived during decompression procedure 1) by maintaining an appropriate transcutaneous pressure gradient of inert gases, and 2) by elevating ambient temperature.

Download Full-text

The Vasostimulant Effect of the Electric Pulse Stimulator on the Cutaneous Blood Flow.

Nishi Nihon Hifuka ◽

10.2336/nishinihonhifu.59.255 ◽

1997 ◽

Vol 59 (2) ◽

pp. 255-256

Author(s):

Yuka NAKAMURA ◽

Shinichi WATANABE ◽

Hisashi TAKAHASHI ◽

Atsuhiko HASEGAWA

Keyword(s):

Blood Flow ◽

Electric Pulse ◽

Cutaneous Blood Flow ◽

Cutaneous Blood

Download Full-text

TEMPERATURE REGULATION IN EXERCISE

PEDIATRICS ◽

10.1542/peds.32.4.691 ◽

1963 ◽

Vol 32 (4) ◽

pp. 691-702

Author(s):

Sid Robinson

Keyword(s):

Blood Flow ◽

Body Temperature ◽

Heat Stroke ◽

The Body ◽

Physiological Regulation ◽

Temperature Changes ◽

Metabolic Heat ◽

Warm Blood ◽

Hot Environments ◽

Large Increments

The central body temperature of a man rises gradually during the first half hour of a period of work to a higher level and this level is precisely maintained until the work is stopped; body temperature then slowly declines to the usual resting level. During prolonged work the temperature regulatory center in the hypothalamus appears to be reset at a level which is proportional to the intensity of the work and this setting is independent of environmental temperature changes ranging from cold to moderately warm. In hot environments the resistance to heat loss may be so great that all of the increased metabolic heat of work cannot be dissipated and the man's central temperature will rise above the thermostatic setting. If this condition of imbalance is continued long enough heat stroke will ensue. We have found that in a 3 mile race lasting only 14 minutes on a hot summer day a runner's rectal temperature may rise to 41.1°C., with heat stroke imminent. The physiological regulation of body temperature of men in warm environments and during the increased metabolic heat production of work is dependent on sweating to provide evaporative cooling of the skin, and on adjustments of cutaneous blood flow which determine the conductance of heat from the deeper tissues to the skin. The mechanisms of regulating these responses during work are complex and not entirely understood. Recent experiments carried out in this laboratory indicate that during work, sweating may be regulated by reflexes originating from thermal receptors in the veins draining warm blood from the muscles, summated with reflexes from the cutaneous thermal receptors, both acting through the hypothalamic center, the activity of which is increased in proportion to its own temperature. At the beginning of work the demand for blood flow to the muscles results in reflex vasoconstriction in the skin. As the body temperature rises the thermal demand predominates and the cutaneous vessels dilate, increasing heat conductance to the skin. Large increments in cardiac output and compensatory vasoconstriction in the abdominal viscera make these vascular adjustments in work possible without circulatory embarrassment.

Download Full-text

Relation of local skin temperature and local sweating to cutaneous blood flow

Journal of Applied Physiology ◽

10.1152/jappl.1963.18.4.781 ◽

1963 ◽

Vol 18 (4) ◽

pp. 781-785 ◽

Cited By ~ 6

Author(s):

Leo C. Senay ◽

Leon D. Prokop ◽

Leslie Cronau ◽

Alrick B. Hertzman

Keyword(s):

Blood Flow ◽

Skin Temperature ◽

Sweat Gland ◽

Cutaneous Blood Flow ◽

Local Skin ◽

Cutaneous Vasodilatation ◽

Local Skin Temperature ◽

Relationship Of ◽

The Relationship ◽

Cutaneous Blood

The relationship of local skin temperature and the onset of sweating to the local cutaneous blood flow was studied in the forearm and calf. The purpose of the investigation was to appraise the possible relation of sweat gland activity to the cutaneous vasodilatation which has been attributed to bradykinin or to intracranial temperatures. The onset of sweating was not marked by any apparently related increases in the rate of cutaneous blood flow. On the contrary, the onset of sweating was followed often by a stabilization or even a decrease in the level of cutaneous blood flow. The relations of the latter to the local skin temperature were complex, particularly in the forearm. There appeared to be additional unidentified influences, possibly vasomotor, operating on the skin vessels during transitional phases in the relation of skin temperature to blood flow. Submitted on October 15, 1962

Download Full-text