VIBS 305 Lecture Notes - Lecture 15: Inferior Vena Cava, Vas Deferens, Abdominal Internal Oblique Muscle
11 Dec 2017
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Sperm production: temperature must be 34 degrees celsius, thermoregulation, pampiniform venous plexus. Pampiniform: pertaining to a tendril or vine. Network of testicular veins wrap loosely around the testicular artery for countercurrent heat exchange. Artery loses heat to the vein so by the time it reaches the testes, the temperature is less than that of the abdomen. **important for reducing temperature: tunica dartos m. Smooth muscle located in the wall of the scrotum. Contraction reduces surface area available for heat loss (keeps testes warm) Relaxation increases surface area available for heat loss (cools testes down) *important for maintaining temperature (heat: cremaster m. Not under voluntary control- differences in myoneural junctions as compared to other skeletal muscles and numerous smooth muscle cells. Caudal margin of the internal abdominal oblique m. Forms a coat around the spermatic cord. Contraction pulls the testicle closer to the body to increase its temperature important for increasing the temperature of the testes: evaporative cooling of scrotum.
