Reproduction and development Part 5

Question 1

How does the ovarian cycle begin?

Answer 1

With the release of GnRH from the hypothalmus

Question 2

GnRH production of the hypothalmus

Answer 2

stimulates the anterior pituitary to secrete small amounts of FSH and LH

Question 3

FSH and LH stimulates ___growth

Answer 3

stimulate follicle growth: the growing follicles that make estradiol

Question 4

The slow rise of estradiol secretion begins to rise____ and FSH and LH blood levels____

Answer 4

steeply, FSH and LH blood levels increase markedly

Question 5

High concentration of estradiol stimulates

Answer 5

secretion of gonadotropins

Question 6

The result of the secretion of gonadotropins is the

Answer 6

final maturation of the follicle and secondary oocyte

Question 7

The luteal phase follows after

Answer 7

ovulation

Question 8

Negative feedback reduced the secretion of ____ and ___back to low levels

Answer 8

LH and FSH

Question 9

Near the end of the luteal phase, low gonadotropin levels cause the ___to disintegrate, causing a sharp decline in estradiol and progesterone

Answer 9

corpus Luteum

Question 10

The hypothalamus and pituitary now released from the negative effect of the hormones estradiol and progesterone can now begin the next ovarian cycle

True or False

Answer 10

True

Question 11

When do ovarian steroid hormones stimulate the uterus to prepare for the support of an embryo?

Answer 11

Prior to ovulation

Question 12

Estradiol secreted from follicles stimulates the thickening of the ____ so that the proliferative phase coordinates with the ____ phase

Answer 12

endometrium
Follicular phase

Question 13

secretion of nutrients during the secretory phase coordinates with the

Answer 13

luteal phase

Question 14

shedding of the endometrium during the menstrual flow phase leads to the growth of

Answer 14

new ovarian follicles

Question 15

After about 500 cycles, human females undergo

Answer 15

menopause

Question 16

Menopause is the

Answer 16

cessation of ovulation and menstruation (very unusual among animals)

Question 17

Menopause might have evolved to allow mother to provide better care for her

Answer 17

children and grandchildren

Question 18

Menstrual cycles are a characteristic only of

Answer 18

humans and some other primates

Question 19

Is sexual receptivity limited to a time frame?

Answer 19

No but it is limted to a “heat frame.”

Question 20

Estrous cycles are

Answer 20

a characteristic of most mammals

Question 21

What happens in the estrous cycle

Answer 21

1. endometrium is reabsorbed by the uterus, and no fluid flow occurs
2. sexual receptivity is limited to a “heat period.”
3. Length and frequency of estrous cycles vary from species to species. Some animals such as the domestic cat ovulate only upon mating.