Reproductive Hormones

• gamete: cell that fuses with another cell during sexual reproduction
• gonads: organs that make gametes
• male gonad: testes
• male gametes: sperm
• female gonad: ovaries
• female gametes: ova / egg
• Testis: two glands that are suspended within a sac that hang outside of the body called the scrotum
• Testis produce the sex hormones: androgens = androsterone and testosterone
• Testis: stimulate spermatogenesis and secondary sex characteristics (body hair, Adams apple)
• Testis increase sex drive and body oil secretion
• Gonadotropin releasing hormone (GnRH) is released from the hypothalamus and controls the release of LH and FSH from the anterior pituitary
• testosterone production is regulated via negative feedback
• Follicle-stimulating hormone (FSH) promotes and initiates sperm production in Sertoli Cells
• FSH is involved in the development, growth, pubertal, maturation, and reproductive process of the body
• Luteinizing hormone (LH) assists spermatogenesis and stimulates Leydig Cell production of testosterone
• Spermatogenesis is the production and development of sperm cells in the testes.
• FSH acts directly on the seminiferous tubule to produce sperm
• It takes 9-10 weeks from spermatogonium to sperm
• Immature sperm travels from the seminiferous tubules to the epididymis where it stays until sexual arousal
• the body does not constantly produce testosterone
• levels of testosterone are controlled by negative feedback, and regulated by GnHR
• As levels of testosterone decrease in the blood, GnRH is released stimulating the pituitary gland to release LH and FSH which promote testosterone production
• As levels of testosterone increase in the blood GnRH secretion is shut off, no LH and FSH is released, and there is no testosterone production
• The testes produce about 130 million fertile sperm / day
• mens average sperm count has fallen in the last 50 years causing problems with couples conceiving
• Homeostatic imbalance: hypogonadism and testicular cancer
• Hypogonadism is the reduction or absence of hormone secretion or other physiological activity of the gonads causing low testosterone levels
• Testicular cancer is a painless, and firm fixed scrotal mass, most common from ages 20-25
• The female reproductive system is made up of the uterus, ovaries, and fallopian tubes.
• Ovaries are located in the pelvis on either side of the uterus
• Ovaries are connected to each other through fallopian tubes
• Ovaries are the size of an almond
• Ovaries produce sex hormones estrogen and progesterone
• ovaries contain cells called follicles
• Follicles consist of primary oocyte and granulosa cells
• In the female reproductive system FSH is a hormone that is produced in the pituitary gland, is carried to ovaries in the blood and stimulates the ovaries to produce oestrogen
• FSH causes eggs to mature in the ovary
• LH is a hormone that is produced in the pituitary gland and causes mature eggs to be released from the ovary into the fallopian tubes
• LH transforms follicles that have released an egg into corpus luteum
• Corpus luteum is the site of progesterone production