11 12 07 - Reproductive System II

11 12 07 - Reproductive System II - Reproductive System II...

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Reproductive System II Reproductive ducts Pronephric duct-male Pronephros forms anterior part of the animal mesonephros behind that (mesonephric duct) metanephros (in amniotes); has its own duct Vas deferens - originally the pronephric duct that attaches to the testis Lampreys and hagfish lack reproductive ducts The gametes are released into the coelom - when released, the gametes travel into the pronephric duct at the genital pore where they leave the cloaca via the urinary tract The rest of the vertebrates: The testis sends tubules out to make contact with the pronephric duct - in anamniotes, sperm and urine share the duct - in amniotes, the ureter carries urine The pro- and meso-nephros degenerate, leaving the pronephric duct for sperm transport, then called the vas deferens In females, the pronephric duct is not used for egg tansports - in anamniotes, the duct continues to carry urine - in amniotes, the duct degenerates (ureter carries urine) Accessory glands are common among male mammals, but also present in other male animals that fertilize internally (sharks, other ) amniotes - these glands secrete substances that contribute to the nutrition and activity of spermatozoa within the female ducts 2 types of fertilization: external and internal fertilization o External: gametes are released from male and females and fertilization occurs in the outside o Internal fertilization- in female, the eggs are fertilized inside of the body o -male comes along and leaves a glob of sperm/ protein called a spermatophore o The female comes along and picks it up
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This note was uploaded on 08/16/2008 for the course BIOL 276 taught by Professor Johnson during the Spring '07 term at UNC.

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11 12 07 - Reproductive System II - Reproductive System II...

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