Female Reproduction Phys

Question 1

What occurs during the follicular phase of the ovarian cycle?

Answer 1

FSH stimulates development of follicles

Question 2

What occurs during the ovulatory phase of the ovarian cycle?

Answer 2

LH surge causes rupture of the Graafian follicle

Question 3

What occurs during the luteal phase of the ovarian cycle?

Answer 3

LH converts the ruptured follicle to a corpus luteum

Question 4

What occurs to the corpus luteum if fertilization does not occur?

Answer 4

Degenerates to form a corpus albicans

Question 5

What does estradiol do during the follicular phase?

Answer 5

promotes proliferation of the endometrium and primes the uterus for progesterone actions

Question 6

What does progesterone do during the luteal phase?

Answer 6

converts the proliferative uterus to a secretory uterus

Question 7

What is the dominate hormone during proliferative phase?

Answer 7

Estrogens

Question 8

What is the dominate hormone during secretory phase? How long is this phase and what occurs during it?

Answer 8

Progesterone–promotes accumulation of glycogen, increased glandular secretions and increased vascularity
14 days following ovulation

Question 9

What occurs during the menstrual phase?

Answer 9

Prostaglandin-mediated vasoconstriction of spiral arteries and local ischemic injury/inflammation–regression of the corpus luteum

Question 10

What occurs during the late follicular phase?

Answer 10

Blood estradiol reaches a high level that initiates positive feedback and a surge in LH and FSH release–promoting ovulation

At any other time estrogen has a negative feedback on the hypothalamic-pituitary-ovarian axis

Question 11

How do high levels of estradiol during the latte follicular phase cause large surge of LH release?

Answer 11

Enhance the sensitivity of the gonadotrophs to GnRH

Question 12

What type of hormones are estradiol and progesterone? what do they bind to and where?

Answer 12

Steroid hormones–bind to albumin and sex hormone-binding globulins (SHBGs) in serum

Question 13

What enzyme does the ovary have more of than the testis and why?

Answer 13

Aromatase–converts androgens to estrogens

Question 14

Why do the theca cells and the granulosa cells have to work together to produce estradiol?

Answer 14

Theca cells can product testosterone from cholesterol, but the Testosterone cannot be converted to Estradiol because the Theca cell does NOT have Aromatase activity

The Androstenedione (turns into testosterone) is transferred to the Granulosa cell where aromatase activity is present

Also progesterone can NOT be converted to Androstenedione in the granulosa cell due to the absence of 17a-hydroxylase and 17,20-desmolase activity in the granulosa cell—progesterone goes to theca cell where activity of enzymes is present then androstenedione returns to be converted to testosterone and estradiol

Question 15

What does progesterone inhibit?

Answer 15

frequency and intensity of uterine contractions

Question 16

What influences androgens to be converted to estradiol?

Answer 16

LH

Question 17

What is Thelarche?

Answer 17

Breast development

Question 18

What is Adrenarche?

Answer 18

increased secretion of adrenal androgens

Question 19

What does estrogen do to bone?

Answer 19

inhibit osteoclasts–promoting rapid growth and uniting of epiphysis with shafts of long bones to stop growth

Question 20

What does progesterone do for breast development?

Answer 20

promotes development of lobules and alveoli in breasts

Question 21

What promotes the development of secondary sex characteristics and transition to normal ovarian function?

Answer 21

production of steroid hormones —very high sensitivity of gonadotrophin release to negative feedback until puberty

Question 22

What occurs during menopause to the hormones and gonadotrophins?

Answer 22

circulating Sex Steroids decrease—few/no remaining follicles to mature and produce estrogens and progestins

circulating gonadotrophins increase–due to decreased estrogen production—-major spike around menopause–loss of negative feedback on the pituitary and hypothalamus by estrogens and progestogens

Question 23

What is the postmenopausal form of estrogen and where does it come from?

Answer 23

Estrone–produced by muscle and adipose tissue–derived primarily from androstenedione in the adrenal gland and ovary

Question 24

Why are postmenopausal women at high risk for osteoporosis?

Answer 24

Estrogens prevent bone resorption/loss–and postmenopausal women do not produce many estrogens