Reproductive Endocrinology Flashcards
name two gonadotrophis
LH and FSH
which two reproductive hormones are common to both males and females
LH and FSH
Name the reproductive hormones of the female reproductive system (5)
- Gonadotrophin releasing hormone
- Follicle Stimulating Hormone
- Lutinizing hormone
- estradiol
- progresterone
What are the primary sexual hormone in females
Estrogen
- causes endometrial growth
- ovulation
- calcium absorption
estrogen
what are secondary sexual characteristics in the femal and which hormone are these influenced by
- breast development
- flaring of hips
- pubic hair
- muscle/fat ratio
Estrogen
What are three primary stages of the female reproductive system
- follicular
- ovulation
- luteal
True/False: LH and FSH are produced in the pituitary, and estradiol and progesterone are produced in the ovaries.
True
True/False: Estradiol and progesterone secreted from the corpus luteum cause the endometrium to thicken.
True
True/False: Both progesterone and estradiol are produced by the follicles.
False
True/False: Secretion of GnRH by the hypothalamus is inhibited by low levels of estradiol but stimulated by high levels of estradiol.
True
True/False: During the menstrual cycle, progesterone levels rise during the luteal phase of the ovarian cycle and the secretory phase of the uterine cycle.
True
True/False: Menstruation occurs just after LH and FSH levels peak.
False
True/False: Menstruation occurs after progesterone levels drop.
True
True/False: Estrogen levels rise before ovulation, while progesterone levels rise after.
True
Which hormone causes Leydig cells to make testosterone?
FSH
LH
inhibin
estrogen
LH
Which hormone causes FSH and LH to be released?
testosterone
estrogen
GnRH
progesterone
GnRH
Which hormone signals ovulation?
FSH
LH
inhibin
estrogen
Estrogen
Which hormone causes the re-growth of the endometrial lining of the uterus?
testosterone
estrogen
GnRH
progesterone
progesterone
If male reproductive pathways are not cyclical, how are they controlled?
- Negative feedback through inhibin and testosterone
- Inhibin is produced by Sertoli cells when the sperm count exceeds set limits.
- The hormone inhibits GnRH and FSH, decreasing the activity of the Sertoli cells.
- Increased levels of testosterone affect the release of both GnRH and LH, decreasing the activity of the Leydig cells, resulting in decreased testosterone and sperm production.
Describe the events in the ovarian cycle leading up to ovulation.
- Low levels of progesterone allow the hypothalamus to send GnRH to the anterior pituitary and cause the release of FSH and LH.
- FSH stimulates follicles on the ovary to grow and prepare the eggs for ovulation.
- As the follicles increase in size, they begin to release estrogen and a low level of progesterone into the blood.
- The level of estrogen rises to a peak, causing a spike in the concentration of LH.
- This causes the most mature follicle to rupture and ovulation occurs.
True/False: Inhibin is produced by Seritoli cells
True
which hormone controls spermatogenesis and how?
- inhibin
- when the sperm count is too high inhibin inhibits the release of GnRH and FSH, which will cause spermatogenesis to slow down.
- If the sperm count reaches 20 million/ml, the Sertoli cells cease the release of inhibin, and the sperm count increases.
when levels of testosterone rise, testosterone inhibits
- the release of GnRH, FSH, and LH from the hypothalamus and anterior pituitary
which hormone is produced from Leydig cells
testosterone
name the reproductive hormones for males and females
- Gonadotrophins
- Estrogens, progesterones, progestogens
- Anti-estrogens & Anti-progestins
- Androgens & Anabolic agents
- Anti-Androgens
what hormones are used to treat infertility
- gonadotrophins
- estrogen receptor antagonists (Clomiphene and Cyclofenil)
which hormones can be used to treat endometriosis
- Danazol
- binds to estrogen and progesterone and inhibits GnRH release
- Buserelin (GnRH)
what happens when GnRH is present for periods of excess
decreases sensitivity of receptors of pituitary and stop release of FSH/LH
what do anti-estrogens do
- block the receptors for estrogens
- increase GnRH and release of LH/FSH
- increase sperm counts and ovulation
what is the primary use of estrogens, progesterones and progesterin
contraception and HRT
how do progesterone only contraceptives act
- induce change in cervical mucous
- hostile environment for sperm
- endometrium unreceptive to fertilized eggs
are progesterone only contraceptives more or less efficacious that combination estrogen/progesterone
less
How are estrogens used in HRT
- low dose
- use in cyclical administration to avoid endometrial carcinoma
- in menopausal woment menstruation does not occur so lining would not be shed, may cause growths
what is the anti-progestin mifepristone used for
- it is an abortifacient
- causes abortion
- blocks actions of progesterone and prevent implantation
Tamoxifen is an
a) estrogen
b) anti-estrogen
c) progesterone
d) anti-progestin
- anti-estrogen
*
- used in estrogen receptor positive breast cancer
- binds to estrogen receptor and blocks estrogen dependent transcription of cells
Tamoxifen
Androgens and anabolic agents can be used in
- hormone replacement therapy
- under developed gonads
- increasing muscle mass
how do androgens or anabolic agents decrease sperm count
by exerting negative feedback on sertoli cells and hypothalamus
anti-androgens are used to treat
- libido and agression in male sex offenders
- prostate cancer
how do anti-androgens work for treatment of prostate cancer
bind to androgen receptors preventing growth by endogenous androgens
