Seminiferous tubules contain spermatogonia (sperm forming cells) and sertoli cells (contribute to nutrition and maturation of spermatogonia).
Interstitial cells of leydig are in loose connective tissue surrounding seminiferous tubules (secretes male sex hormone)
Describe the location of the testis.
Testis remain in body cavity in all vertebrates except most mammals. In these testis descend into the scrotum.
What is the spermatic cord?
cord carrying sperm duct, blood vessels, nerve from testis in scrotum up through inguinal canal. (canal between body and scrotum)
Describe testis in anamniotes. (Fishes and amphibians)
Testis usually large.
Seminiferous ampullae instead of tubules.
Fat bodies- used in nourishing developing sperm.
Describe the reproductive passages of agnathans.
No ducts, sperm and eggs shed directly into coelom, eixt through genital pore into caudal end of archinephtic duct.
Describe the reproductive passages of Amphibians.
Sperm carried from testies by connecting tubules (efferent ductules) through mesorchium to anterior end of opisthonephric kidney, then through anterior opisthonephric tubules to archinephric duct and on to cloaca.
Describe the reproductive passages of elasmobranchs.
Much of archinephric duct modified as seminal cesicle, which produces seminal fluid used in transport and storage of sperm.
Describe the reproductive passages of amniotes. (reptiles, birds, mammals)
passageways are essentially the same as in amphibians.