Define spontaneous ovulators

when the release of an ova from teh maturing follicle is determined by endogenous stimuli such as hormones

rats

mice

hamsters

dogs

sheep

primates (incl. humans)

Define seasonal breeders

spontaneous ovulators that time their reproduction to the season for optimal food & weather conditions

Define induced/reflexive ovulators

the maturation of follicles and sexual receptivity are induced by exogenous stimuli such as male pheromones or mating

cats

ferrets

rabbits

In induced/reflexive ovulators, there is always a _________________________.

They are always ready to ________ during _____________.

In induced/reflexive ovulators, there is always a mature follicle ready or on its way.

They are always ready to be receptive during the breeding season.

NOTE: slide recommends review of table 4.1 in text

ovulation

breeding

receptivity

(note: this is an abbreviated list of table 4.1)

the 'ovulation' criteria for classifying femal repro. cycles classifies species into these 2 categories

a) ovulation under cyclic hormonal control ('spontaneous ovulation')

or

b) ovulation under control of external stimuli and cues ('reflexive ovulation')

the 'breeding' criteria for classifying female repro. cycles classifies species into these 2 categories

-seasonal

or

-year-round

the 'receptivity' criteria for classifying female reproductive cycles classifies species into these 2 categories

a) limited to periovulatory period (which is the actual meaning of 'estrus')

or

b) throughout cycle

The existence of cycles results from the increase and decrease of _____________ to cause __ behavior and ___.

(good examples of ___ and ___  ____)

The existence of cycles results from the increase and decrease of many hormones to cause sexual behavior and ovulation.

(good examples of negative and positive feedback)

Cycles can be as short as __ or as long as __ .

In females the events of the cycle are similar even in ____________________.

What is the rate limiting step with regard to cycles?

Cycles can be as short as 4-5 days or as long as a year.

In females the events of the cycle are similar even in cycles of different lengths.

What is the rate limiting step with regard to cycles? - the maturation and release of the egg

Some animals don't cycle naturally, but are induced to ovulate.

(see table 4.1 in text)

The ovarian cycle:

1) __ from the hypothalamus causes ___ and __ to be released from the __ pituitary and stimulate the ovary to produce ___.

--) __ stimulates the immature ___ to grow (this is where the __ is)

2) The rising levels of __ in teh blood cause further increase in ___ and ultimately lead to a __ surge (which is __ feedback)

[parts 3-5 on next flaschard]

The ovarian cycle:

1) GnRH from the hypothalamus causes LH and FSH to be released from the anterior pituitary and stimulate the ovary to produce E.

--) FSH stimulates the immature follicle to grow (this is where the egg is)

2) The rising levels of E in teh blood cause further increase in GnRH and ultimately lead to a LH surge (which is positive feedback)

The ovarian cycle:

3) The __ surge leads to __ and also helps stimulate the formation of the __________.

4) After release of the __, the __ levels of __ and __ reduce the release of ___,  and then __ and __ (which is __ feedback)

5) finally, __ synthesis in the ___ is reduced

The ovarian cycle:

3) The LH surge leads to ovulation and also helps stimulate the formation of the corpus luteum.

4) After release of the egg, the high levels of E and P reduce the release of GnRh, and then LH and FSH (which is negative  feedback)

5) finally, steroid synthesis in the ovary is reduced

Prior to ovulation, ___ feedback causes ___ in GnRH release.

 After ovulation, __ feedback causes __ in GnRH release.

Prior to ovulation, positive feedback causes increase in GnRH release.

 After ovulation, neagative feedback causes decrease in GnRH release.

What are the 4 phases of the human reproductive cycle?

- Follicular phase

- Periovulatory period

- Luteal phase

- Menstrual phase

In the follicular phase of the human reproductive cycle, where is GnRH released from and when is it released?

released from the hypothalamus

after the bleeding of menstruation ceases

In the follicular phase, what is brought about by the levels of FSH and what is this process called?

the development of several follicles

known as 'recruitment'

In the follicular phase, what does LH lead to?

increased steroidogenesis

In the follicular phase, how many follicles will regress or die?

What happens to the rest?

How can this process be overridden?

In the follicular phase, how many follicles will regress or die?

all but one

What happens to the rest?

the single dominant follicle proceeds to ovulation

How can this process be overridden?

by fertility drugs

How long is the follicular phase in humans? in rodents?

12-14 days in humans, 2-3 days in rodents