Lecture 11: Reproductive Drugs
What is normal ovulation/menstrual cycle?
A complex interaction between the hypothalamus, pituitary gland and the ovaries leads to the process of ovulation that is repeated with an average period of 28-30 days.
What is the combination pill?
Also called oral contraceptives or just the "pill", this method uses the hormones estrogen and progestin to prevent ovulation. (The method is highly effective if the woman remembers to take her pill consistently at about the same time each day.)
The menstrual cycle is controlled by cyclic release of
FSH and LH estrogens
The synthesis and release of hormones are controlled by....
GnRH, LH and FSH.
Estrogens induce secondary sex characteristics such as what?
breast development and increased deposition of subcutaneous fat especially in the hips and breasts.
Define hormones
chemical substances made in the body that are essential for every activity of daily living, including the processes of digestion, metabolism, growth, reproduction, and mood control
Define estrogen
female sex hormones produced primarily by ovary
What does FSH stand for?
follicle stimulating hormone
What is the major use of androgens in clinical situations?
for replacement therapy in men whose production of testosterone is impaired.
Why is gonadotropin releasing hormone (GnRH) needed?
for sexual maturity and normal reproduction. GnRH stimulates the anterior pituitary gland to release several hormones
With the onset of puberty, the hypothalamusincreases the release of...
gonadotropin releasing hormone (GnRH)
What are serious side effcts of oral contraceptive pills?
high blood pressure and formation of blood clots. Minor side effects of oral contraceptive pills are nausea and vomiting, breast swelling and tenderness, headaches, mood changes, and weight gain.
Emergency contraceptives contain ______ levels of a hormone found in daily oral contraceptives
higher
How does the combined oral contraceptive pill work in birth control?
prevent pregnancy by inhibiting ovulation, as a result of suppression of the pituitary gland's release of hormones LH and FSH that stimulate ovulation by high levels of estrogen and progestin. The combination agents also produce a change in the cervical mucus and in the uterine endometrium, which decrease the likelihood of conception and implantation.
Estrogens promote oogenesis and stimulate the development, growth, and maintenance of what?
reproductive and accessory organs
The most important androgen in humans
testosterone
What are oral contraceptives?
With hormonal birth control, a woman takes hormones similar to those her body makes naturally. These hormones prevent ovulation. When there is no egg to be fertilized, pregnancy cannot occur. Oral contraceptives consist of progestin only (the so-called mini pill) or a combination of estrogen with progestin (the combination pill).
What is Mifepristone (Mifeprex or RU486)
a synthetic potent antiprogestogen, which was approved September, 2000 by FDA for early termination of pregnancy
The hormone released by the hypothalamus beginning at the onset of sexual maturity in both males and females is: a. follicle-stimulating hormone (FSH) b. lutenizing hormone (LH) c. progesterone d. estrogens e. gonadotropin releasing hormone
e. gonadrotropin releasing hormone (GnRH)
Define progestogens
the most important progestogen produced both in female (secreted by the corpus luteum that forms from remains of ovarian follicle that ruptured at the time of ovulation), primarily during the second half of the menstrual cycle and by the placenta and in males (secreted by the testes) in response to LH
What is antiestrogen or estrogen therapy used for?
treatment of breast cancer and prostate tumors
The most effective reversible method for preventing pregnancy in the United States
hormone based oral contraceptives
Menstruation
when The remains of the deteriorated endometrium and its supply of blood are discharged through the vagina. he discharge of disintegrating tissue lasts for an average of five days. A new egg also begins to develop during menstruation.
How does the mini pill work?
when progesterone is provided prior to ovulation (in normal menstrual cycle, progesterone is produced by corpus luteum after ovulation), it inhibits ovulation by suppressing the LH.
Possible side effects of mifepristone
will cause vaginal bleeding. In some cases the vaginal bleeding can be very heavy. In a few cases, this bleeding will need to be stopped by a surgical procedure. Other possible side effects of the treatment include diarrhea, nausea, vomiting, headache, dizziness, back pain, and tiredness.
What pituitary hormone(s) control ovulation and production of female hormones by the ovary? a. estrogen b. gonadotropin releasing hormone c. follicle stimulating hormone (FSH) and lutenizing hormone (LH) d. progesterone
FSH and LH
How does mifepristone (RU486) work in abortion?
It binds to the progesterone receptor, preventing binding of endogenous progesterone to the receptor which is needed for pregnancy to continue (progesterone that binds to the receptor prepares the endometrium for implantation and maintenance pregnancy.) Mifepristone, when used together with another medicine called misoprostol, is used to end an early pregnancy (70 days or less since your last menstrual period began).
What is reproduction?
Reproduction in humans, and others mammals, is the process by which sperm and egg cells are produced, brought together, join and develop into a new individual
What is the minipill?
The "mini-pill" is a type of birth control pill that contains only progestin, no estrogen. It is an alternative for women who are sensitive to estrogen or cannot take estrogen for other reasons.
How do the gonadotropins "follicle stimulating hormone" (FSH) and "lutenizing hormone" (LH)act?
These gonadotropins act by stimulating the production of sex hormones in the gonads (testes and ovaries). In both sexes, the gonads have a dual function: the production of eggs and sperm (female gonads, ovaries, produce eggs; male gonads, testes, produce sperm) and the secretion of sex hormones. It is the interaction of the gonadotropins and the sex hormones that controls the reproductive cycle.
These hormones are responsible for development of the male reproductive organs during embryonic development and the development of secondary sexual characteristics (beard, deeper voice).
testosterone
Define sex hormones
chemicals produced by the body that are necessary for conception, embryonic maturation, and development of primary and secondary sexual characteristics at puberty
How do we control fertility
contraceptives
Besides the ovary, which gland can also synthesize estrogens?
the adrenal gland (in men and post menopausal women)
Define androgen
hormones that have anabolic and/or masculinizing effects in both males and females.
What is the main clinical use of progestogens?
in contraception, where they are generally used with estrogens.
The effectiveness of progestin-only oral contraceptives is ____ than that of the combination type
less than
What does LH stand for?
lutenizing hormone
Estradiol
major estrogen produced by women
What do estrogens do in the cervix to assist in sperm entry?
mucous production
Plan B contains only this hormone
only progestin
Which hormone aids in the maintenance of pregnancy and inhibits uterine contraction. High level of this hormone inhibits the ovulation.
progesterone
Which of the following hormones, normally produced in the corpus luteum that inhibits ovulation, is a common component of oral contraceptives? a. testosterone b. follicle-stimulating hormone (FSH) c. lutenizing hormone (LH) d. progesterone
progesterone
Where is testosterone synthesized in males and where is it synthesized in females
testes, cells in the ovary of the female and in the adrenal gland