What does GnRH stand for?
Gonadotropin releasing hormone.
Gandalf represents hell.
Gonadotropin luteninsing hormone.
What is the purpose of GnRH?
The hypothalamus stimulates cells in the anterior pituitary gland to produce LH and FSH.
To encourage the body to be sexually active.
To encourage the body to ovulate.
What is LH?
Luteinising hormone.
Follicle stimulating hormone.
Loose haddock.
What is FSH?
Fashionable sassy haddock.
What is the purpose of LH?
To stimulate cells in the testes to produce testosterone.
To stimulate spermatogenisis.
Both.
Neither.
What is the purpose of FSH.
Tick all that applies to dihydrotestosterone.
Prenatal development.
Development of male sexual characteristics.
Development of sexual function.
Stimulation of anabolism.
Development of female sexual characteristics.
Growth of testis.
What hormone promotes development and maintenance of female reproductive structures, feminine secondary sex characteristics and breasts.
Estrogen.
Progesterone.
Relaxin.
Inhibin.
What hormones inhibits release of FSH and, to a lesser extent, LH?
The oestrous cycle is the time from the beginning of heat to the period of the next, but what does polyestrous describe?
The cycle continues throughout the year if not pregnant.
Has 2 cycles per year.
Has 1 cycle per year.
What does Diestrous describe?
What does monoestrous describe?
Select an animal that is polyestrous.
Cattle.
Fox.
Dog.
Select an animal that is diestrous.
Select an animal that is monoestrous.
There are 3 phases of the estrous cycle, what is the first?
Follucular.
Ovulation.
Luteal.
Second?
Third?
What step does this describe? GnRH triggeres FSH release that stimulates growth of follicles in the ovary?
Follicular.
What step does this describe? BnHR and estrogen level changes will trigger LH release that causes ovulation.
What step does this describe? CL producing progesterone that affects the uterus lining.
FSH and LH are secreted by the anterior pituitary gland but where is estrogen secreted from?
Ovaries.
Anterior pituitary gland.
Thyroid glands.
Throughout the cycle FSH it stimulates follicle development and what else?
Follicle releases estrogen.
FSH stimulates the ovaries to release estrogen.
Estrogen, what does it do?
Estogen stimulates the uteus lining to thicken.
Estrogen inhibits FSH being released from pituitary gland.
Estrogen concentration peaks and stimulates the anterior pituitary to release LH and FSH then the LH surges to rapid increase and does what?
Ovulation stimulated by LH – follicule ruptures and egg is released.
Ruptured follicle turns into corpus luteul.
CL releases progesterone.
All.
None.
Progesterone rises and what?
Progesteron inhibits FSH and LH.
Uterus lining is maintained by progesterone.
If no embryo, the CL breaks down and stops releasing progesterone.
All of the above.
The concentration of progesterone then falls and...
FSH and LH concentrations increase because they are no longer inhibited by progesterone.
Uterus lining not maintained.
Uterus lining sheds out.
Cycle starts again.
Label this diagram with the correct hormones.
Label this.
What is the first stage of the estrous cycle?
oestrus. – the female is receptive to the male.
Metoestrus – formation of corpus luteum.
Diestrus – corpus luteum fully functional.
Proestrus – regression of corpus luteum, drop in progesterone, extends until start of oestrus.
What is the third stage.
Proestrus – regression of corpus luteum, drop in progesterone, extends until start of estrus.
In cattle oestrus lasts 4-24hrs, and ovulates 30h after. When does metoestrus occur?
2-4 days after oestrus, ovulation and formation of CL.
around day 5, ends with regression of CL
Diestrus occurs on the 5th day, ends with regression of CL on day 16, if the cattle is not pregnant CL will degenerate, then proestrus occurs but what happens?
Drop in progesterone.
Increase in progesterone.
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