ABSTRACT
1. In neutral environmental temperatures, shivering was induced in sheep by intra-ruminal cooling. Shivering was then depressed for a period by intra-abdominal heating. Intra-abdominal heating without ruminal cooling induced panting and a reduction of caval temperatures. Posterior caval temperatures were found to be inappropriate to the responses observed.2. Intra-abdominal heating of sheep in cold and warm environments depressed shivering and augmented panting respectively. Unilateral splanchnotomy abolished these responses on the ipsilateral side.3. The results are interpreted to indicate that the thermoreceptors stimulated lie within the walls of the rumen and intestine, and possibly the mesenteric veins.4. The splanchnic nerves are indicated as the afferent pathway for these receptors, and differential splanchnic innervation of the gut is suggested to explain unilateral abolition of the response to warming.
Subject(s)
Abdomen/physiology , Sensory Receptor Cells/physiology , Thermosensing , Animals , Body Temperature Regulation , Female , Hot Temperature , Intestine, Large/innervation , Intestine, Small/innervation , Mesenteric Veins/innervation , Respiration , Rumen/innervation , Sheep , Shivering , Splanchnic Nerves/physiology , Sympathectomy , Thermoreceptors/physiologySubject(s)
Abdomen , Body Temperature Regulation , Hot Temperature , Animals , Body Temperature , Metabolism , Respiration , Sensory Receptor Cells/physiology , Sheep , Skin TemperatureSubject(s)
Abdomen/blood supply , Body Temperature Regulation , Hot Temperature , Respiration , Rumen/innervation , Sensory Receptor Cells/physiology , Sheep/physiology , Veins/innervation , Animals , Female , Hypothalamus/physiology , Laparotomy , Oxygen Consumption , Skin Temperature , Spinal Cord/physiology , Vagina/blood supplyABSTRACT
When electrical heat sources were implanted in the abdominal cavities of sheep and heated to dissipate 20 to 22 watts of additional endogenous heat in the animal, a rapid increase in respiratory frequency and respiratory water loss occurred 3 to 5 minutes after the initiation of heating. The response was accompanied by a marked decline of the temperature of the hypothalamus, with an increase of less than 1.0 degrees C in skin temperature over the location of the heaters in the abdomen. When the same skin area was heated externally in the absence of internal heating, no significant response was seen. The results support the concept of the existence of thermoreceptors, located in deep tissues or veins, which play a role in the regulation of body temperature.
