PubMed · 16130575
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
Peggy Theilig. 2003. [The kangaroo method]].. https://pubmed.ncbi.nlm.nih.gov/16130575/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Explore the source record for details and available documents.
The temperature in human testis is 2-3 degrees C less than that of body providing a suitable environment for sperm production. Pampiniform plexus play a major role in this. Authors question the full function of Pampiniform plexus; if it is sufficiently efficient to maintain the optimal temperature, why testes are not retained in abdomen. The present hypothesis states that during the process of spermatogenesis a large amount of heat is liberated as a bye product of energy utilization. Testes are purposefully kept away in the dangling scrotum to exclude the damage otherwise it would have caused to visceral organs from the heat it produced. The heat from testes is carefully liberated by scrotum. The thin skin with no subcutaneous fat, scanty hair distribution and presence of more sweat glands on it permits easy escape of heat. On exposure to cold, the scrotal surface area is minimized by rugosities for heat conservation and cremaster muscles lift testes closer to abdomen to provide heat to body.
The heated necrotic element created by a single high intensity focused ultrasound exposure can be considered as the foundation of high intensity focused ultrasound ablation of tumour lesions. In this paper, we studied the effects of exposure dose and focal depth in tissue on heated necrotic elements, using numerical simulation and experiment. The acoustic field of one of the transducers for the Model-JC HAIFU focused ultrasound tumour therapeutic system was modeled using O Neill's equation, and then using this information together with Pennes' bio-heat-transfer-equation and finite difference techniques, the heated necrotic element was simulated numerically. The results showed that the theoretical predictions were basically in agreement with the experimental data for low exposures, but that the experimental values suddenly increased with the increasing exposure and exceeded the theoretical predictions. The element volume from the theoretical prediction and experiment for the heated necrotic element decreased with increasing focal depth in tissue for a given exposure, and the theoretical predictions were a little lower than the experimental ones. Therefore, heated necrotic elements created by high intensity focused ultrasound can be well predicted from a knowledge of ultrasonic biophysics theories.