Lect. 4 - prep for preg and ovulation

Question 1

When does ovulation occur in the ovarian cycle?

Answer 1

day 14 of and average 28 day cycle

Question 2

What roles do FSH and LF play in ovulation?

Answer 2

a rise in FSH and LH (sharp rise) stimulate ovulation ( they also contribute to the overall control of the menstrual cycle)

Question 3

What is the source of estradiol during the folliclular phase?

Answer 3

granulosa cells of the developing follicle

Question 4

What is estradiol responsible for in the folliclular phase?

Answer 4

The proliferation phase of the endometrium

Question 5

What is the source of progesterone in the ovarian cycle?

Answer 5

Thecal cells that make up the outer part of the Graafian follicle remaining after ovulation.

Question 6

What components of the Graafian follicle make up the corpus luteum?

Answer 6

residual theca and granulosa cells

Question 7

What is the fate of the corpus luteum in the absence of fertilization?

Answer 7

It regresses, decreasing levels of progesterone and estradiol, resulting in the beginning of the next menstrual phase

Question 8

What role does inhibin play in the menstrual cycle?

Answer 8

Inhibits secretion of gonadotropins, especially FSH, resulting in the regression of the corpus luteum.

Question 9

3 phases of the endometrial cycle and their durations.

Answer 9

Menstrual phase (days 1-4 or 5)
 Proliferation phase (days 4-14)
Secretory phase (days 15-28)

Question 10

The menstrual phase of the endometrial cycle

Answer 10

Endometrial build-up from the previous cycle sloughs off (=menstrual flow).

Question 11

What is the role of the spiral arteries in the menstrual phase of the endometrial cycle?

Answer 11

Menstruaton begins w/ vasoconstriction of the spiral arteries that have been supplying the endometrium, followed by local ischemia

Question 12

What factors contribute to the vasoconstriction of the spiral arteries?

Answer 12

prostaglandins

Question 13

Proliferation phase of the endometrial cycle

Answer 13

Endometrial growth increases the endometrial thickness from 1-2mm to 8-10 by day 14.

Question 14

Factor responsible for the proliferation phase of the endometrial cycle

Answer 14

increase levels of estradiol - secreted by the granulosa cells of the developing ovarian follicle

Question 15

Secretory phase of the endometrial cycle

Answer 15

Endometrial growth stops, mucous glands develop more and begin secretion. Area becomes more vascularized.

Question 16

Factor responsible for the secretory phase of the endometrial cycle

Answer 16

rising levels of progesterone, secreted by granulosa and thecal cells of the ovarian follicle

Question 17

What is the major factor that leads to menopause in females?

Answer 17

no follicles left to produce estradiol and progesterone

Question 18

What are the characteristic of the Graafian follicle immediately prior to ovulation?

Answer 18

oocyte arrested in diplotene of prophase 1; follicle expands; completion of meiosis I; second arrest at metaphase II; formation of stigma

Question 19

What factors are involved in the process of ovulation

Answer 19

LH surge; increased blood flow; thickening of outer follicle layers; release of - edema, prostaglandins, histamine, vasopressin, plasminogen activator; production of metalloproteinases; secretion of HA; inflammatory action

Question 20

What is ovulated?

Answer 20

Ovum at metaphase II; 1st polar body; zona pellucida; corona radiata; expanded cumulus oophorus

Question 21

Fertilization Age system

Answer 21

Date age of embryo from time of fertilization

Question 22

Menstrual Age system

Answer 22

Date age of embryo from start of mother’s last menstrual period. 2 weeks greater than fertilization age.