Lec 10 Reproduction 3-1

Gradually a net loss of secretory mass occurs

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Unformatted text preview: mass occurs. Pregnancy - 5 months Pregnancy High levels of progesterone cause the lobules to High grow big enough so that they can make milk grow The lobules crowd out the fat Mouse Mammary Development is Similar to Humans Mice can be used as a model for breast development Developmental Blocks of P and Prolactin (Prl) Receptors (Progesterone receptor) (Prolactin Receptor) Hormonal Regulation of Lactation Hormonal Also, at least five other hormones are Also, needed for normal development and milk synthesis: synthesis: (1) Growth hormone or somatotropin (2) ACTH (adrenocorticotropin hormone) (3) TSH (thyroid stimulating hormone) (4) Cortisol (5) Thyroxine Hormonal Regulation of Lactation Ho rm o na l R e g ula tio n o f Milk Ho R e le a s e (e) Milk release or let‑down Dependent on a “suckling reflex” under neurohormonal control Suckling stimulates a nerve reflex within the nerve cells of the teat . Ho rm o na l R e g ula tio n Ho Posterior Pituitary (brain): Releases o xyto c in into blood Causes contraction of the m yo e p ith e lia l c e lls lining the alveoli and ducts Results in m ilk re le a s e o r le t‑d o wn This suckling reflex can be conditioned for ex. baby crying in humans. Mini review Mini What happens during Pro, Estrus, Metestrus, Diestrus Negative Feedback Follicular Stages GnRH Parts of female repro tract. Ovary, infundibulum, oviduct, uterus, cervix, vagina vulva Parts of the male reproductive tract Testes, scrotum, epididymis, vas deferens, urethra, sex glands, penis A.I. – advantages Effects of males on reproduction Genetic improvement, many offspring, no STDs, no injuries Functions of placenta respiration, nutrition, excretion, hormone production Gestation, Parturition Oxytocin...
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This note was uploaded on 10/21/2013 for the course ANIMAL SCI 101 taught by Professor Dr.sharma during the Fall '12 term at Rutgers.

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