Cycle, Ovulation And Pregnancy Prep

Question 1

Ovarian cycle - Follicular phase

Answer 1

Days 1 to 14

Development of the mature Graafian follicle and secondary oocyte in the ovary
FSH from anterior pituitary, FSH-releasing factor from hypothalamus

Question 2

Whatis the source of estradiol in the follicular phase? What does it do?

Answer 2

Granulosa cells ssecrete estradiol, proliferation phase of endometrium

Question 3

When is ovulation?

Answer 3

Day 14 of the cycle

Ovulation is stimulated by rise in FSH and sharp rise in LH (anterior pituitary)

Question 4

What is the source of progesterone?

Answer 4

After ovulation the outer part of the Graafian follicle remains behind and the thecal cells secrete progesterone

Necessary for implantation of a fertilized egg

Question 5

What is the corpus luteum composed of? When does it come about?

Answer 5

Residual teca and granulosa cells form a large glandular structure, the corpus luteum

The Leteal phase after ovulation

Question 6

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

Answer 6

It regresses, levels of progestrone and estradiol decrease, next mentrual phase begins

Breakdown due to apoptosis, uterine luteolytic factors

Question 7

What does inhibin do?

Answer 7

Inhibits secretion of gonadotropins, FSH, resulting in reegression of corpus luteum.

Released by granulossa cells q

Question 8

What are the phases of the endometrial cycle?

Answer 8

Menstrual phase - days 1-4,5
Proliferation phase - days 4-14
Secretory phase - days 15-28

Question 9

What’s the mentrual phase, how do spiral arteries play a role?

Answer 9

The endometrial build up sloughs off

Begins with the vasocontriction of the spiral arteries - mediated by protaglandins

Question 10

What is the proliferation phase?

Answer 10

Endometrial growth, thickness increased to 8-10mm

Blood vessels and glands also grow

Growth due to increased levels of estradiol secreted by granulosa cells

Near end: sharp rise in estradiol

Question 11

Secretory phase

Answer 11

Endometrial cycle

Estrogen decrease and endometrial growth stops

Mucous glands develop, spiral arterioles expand

Controlled by rising levels of progesterone by granulosa and thecal cells of ovarian follicle

Question 12

Menopause

Answer 12

All the follicles have either degenerated or have undergone ovulation

Question 13

What is ovulated?

Answer 13

Ovum at metaphase II
-and polar body
Zona pellucida
Corona radiate
Expanded culus oophorus

Question 14

Ovulation, process and all factors invuled

Answer 14

LHsurge, 24 hours before is the actual cuse - from anterior pituitary

Increased blood flow to follicle wall

Thickening of outer layers of follicle

Release of fluid and other compounds from blood vessels: edema, prostaglandins, histamine, vasopressin, plasminogen activator

Production of matris metalloprotinases: degrade extracellular matrix