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Unformatted text preview: lar Thermoregulation Sperms are not produced at core body temperature
In the scrotum, the testes are kept 23°C cooler than in the pelvic cavity. This is essential for sperm production. Cooling mechanisms The cremaster muscle contains strips of the internal abdominal oblique muscle (skeletal muscle) around the spermatic cord. It can elevate or lower the testes. The dartos muscle is a subcutaneous layer of smooth muscle that wrinkles skin reducing surface area of scrotum. Can lifts testis upwards
The pampiniform plexus is an extensive network of veins that surround the testicular artery in the spermatic cord, keeping the testes cooler countercurrent heat exchange that cools arterial blood entering testis The Scrotum
The Scrotum Figure 27.2 Cremaster muscle Countercurrent Heat Exchanger
Countercurrent Pampiniform plexus Connection between testis and the
body The structures that connect the testis with the body are enclosed within a connective tissue sheath called the spermatic cord Blood vessels
Nerve fibers PNS and SNS
Cremaster muscle The Testes
The Testes Each testis is surrounded by two tunics: The tunica vaginalis, derived from peritoneum The tunica albuginea, the fibrous capsule of the testis Septa divide the testis into 250300 lobules, each containing 14 seminiferous tubules
Seminiferous tubules where ____ is pro...
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