388 TEMPERATURE-TOPOGRAPHY. 



Therefore the temperature in fast runners may rise above 40. The increase 

 in temperature following vigorous muscular activity disappears about one and 

 a half hours after the commencement of rest. The lower temperature of par- 

 alyzed muscles is due only in part to the absence of muscular contractions. 



(c) With reference to the influence of the sensory nerves upon the 

 temperature it should in the first place be noted whether the circu- 

 lation is increased or diminished as a result of their stimulation, 

 whether respiration is slowed or accelerated, and whether the muscula- 

 ture of the body is relaxed, or is stimulated to activity through reflex 

 influences. In the first place the temperature, in the interior of the 

 body and the rectum, will be increased, and in the latter diminished. 

 From this point of view the conflicting statements not rarely made can 

 be reconciled. 



(d) The bodily temperature rises also (about 0.3) as the result 

 of mental activity. The brain itself acquires a higher temperature in 

 consequence of sensorial or sensory stimulation. 



(e) The parenchymatous fluids, the serous fluids and the lymph 

 generate but little heat within themselves by reason of the slight 

 metabolic changes that take place in them, and accordingly their tem- 

 perature is that of their environment. The epidermoidal and horny 

 tissues produce no heat at all, and therefore maintain their temperature 

 from the subjacent tissues. 



2. The temperature of an organ depends upon the amount of blood 

 it contains, as well as upon the time within which the volume of blood 

 is renewed. 



This is seen most distinctly in the differences in temperature between cold, 

 pale skin, and warm, reddened skin. 



When Becquerel and Brechet compressed the axillary artery in a man, the 

 temperature in the interior of the biceps muscle of the arm fell several tenths of 

 a degree. After ligation of the crural artery and vein in dogs Landois observed 

 the temperature decline several degrees. Long-continued elevation of the ex- 

 tremities deprives them of blood and causes them to become colder. 



Attention should be called at this point to a difference between the internal 

 and external portions of the body, which is especially emphasized by v. Lieber- 

 meister. The external portions of the body give off more heat to the exterior 

 than they generate within themselves. They will, therefore, be the cooler the 

 more slowly the blood flows into them ; and the warmer the more rapid the blood- 

 current. Acceleration of the blood-current, therefore, will cause greater uniformity 

 in temperature between the peripheral portions and the interior of the body, 

 while retardation of the blood-current causes greater uniformity in temperature 

 between the peripheral portions of the body and the surrounding medium. The 

 internal portions of the body react in exactly the opposite manner. Here active 

 production of heat takes place, while heat-dissipation occurs almost solely through 

 the blood-current. The temperature in these parts must, therefore, fall when the 

 blood-current is accelerated, and the reverse. From this it follows that the 

 greater the difference in temperature between the periphery and the interior of 

 the body, the less is the rapidity of the circulation. 



3. If the situation of an organ causes it to lose much heat by con- 

 duction and radiation, or if other conditions bring about the same result, 

 the temperature of the organ declines. 



In the first place the skin is again to be mentioned in this connection, as it 

 must exhibit a different temperature accordingly as it is exposed to colder or 

 warmer surroundings, or is covered or not, or is dry or moistened by perspiration 

 (in the evaporation of which heat is lost) . The ingestion of considerable amounts 

 of cold food and drink must cause the temperature of the stomach, and the inhala- 

 tion of cold air must cause that of the respiratory tract down to the bronchial 

 tree, to fall. 



