THESE GONADOTROPHINS STIMULATE THE NORMAL FUNCTIONING OF THE GONADS AND THE SECRETION OF SEX HORMONES IN BOTH MEN AND WOMEN. IN WOMEN, FOLLICLE-STIMULATING HORMONE STIMULATES THE DEVELOPMENT AND MATURATION OF THE FOLLICLES AND OVA. AS THE FOLLICLE DEVELOPS IT PRODUCES OESTROGEN IN INCREASING AMOUNTS WHICH AT MID-CYCLE STIMULATES THE RELEASE OF LH. THIS CAUSES RUPTURE OF THE FOLLICLE WITH OVULATION AND CONVERTS THE FOLLICLE INTO THE CORPUS LUTEUM WHICH SECRETES PROGESTERONE. IN MEN, LUTEINISING HORMONE STIMULATES THE INTERSTITIAL CELLS OF THE TESTIS TO SECRETE TESTOSTERONE, WHICH IN TURN HAS A DIRECT EFFECT ON THE SEMINIFEROUS TUBULES.