BIOM 3200 Lecture Notes - Lecture 1: Lactiferous Duct, Prolactin, Y Chromosome
8 Mar 2017
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And thyroid hormones as well as progesterone which helps stimulate the development of the mammary alveoli: prolactin, stimulates the mammary glands to make milk proteins after birth. Sensory endings in the breast, activated by the stimulus of suckling, relay impulses to the hypothalamus and inhibit the secretion of pih. Sex determination: autosomal and sex chromosomes: each zygote inherits 23 chromosomes from its mother and 23 chromosomes from its father. The hypothetical substance that promotes their conversion to testes has been called the testis- determining factor (tdf). In females, the y chromosome must be absent for pathways directed by genes in the x chromosomes to result in the development of ovaries. It has been shown that the gene for the testis-determining factor is located on the short arm of the y chromosome. The sertoli cells appear at about day 42. At about day 65, the leydig cells appear in the embryonic testes.
