ANSC 340 Lecture Notes - Lecture 7: Abdominal Internal Oblique Muscle, Tunica Vaginalis, Dartos
9 Sep 2016
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Striated muscle (attached to skeleton by tendons under voluntary control) Pumping action to facilitate blood flow and cooling efficiency. Layers: (outside - - > in: skin, tunica dartos: **muscle** Sustained contraction- brings testis closer for warmth: scrotal fascia, parietal tunica vaginalis. **for ideal sperm production, scrotal temp is 5 degrees c below body temp** Scrotal control regulated by: dartos muscle- contraction. Relaxes in heat: cremaster muscle- helps blood flow through pampiniform plexus (as part of heat exchange, pampiniform plexus- heat exchange. Looks like web of veins (which allow for heat exchange) wrapped around artery (which moves blood) [cooling blood into testicle, warming blood back up] As scrotal temp increases, sends signal to brain. Larger scrotum surface area = better heat exchange. Causes decreased/hindered ability for sperm production aka artificial cryptorchid (testicles don"t descend) Due to testosterone which promotes lean muscle production which means no marbling (thus not widely accepted/popular) Effects of extra fat in scrotum on testis thermoregulation:
