Female Reproductive System

Question 1

E3

Answer 1

Principal estrogen of pregnancy

Question 2

Thecal Cells

Answer 2

In close proximity to blood vessels and have the capacity to form androgens

=>Secreted to granulosa cells

Question 3

Granulosa cells

Answer 3

Possess aromatase enzymes capable of converting androgens to estrogen; also possess 17B-hydroxysteroid dehydrogenase

*Respond to circulating FSH

Question 4

Primordial follicle

Answer 4

Primary oocyte separated by layer of poorly differentiated granulosa cells

*Layers communicate w/ gap jnxns

Question 5

GPR 3

Answer 5

Arrests the primordial follicle in the diplotene stage of Prophase I

Question 6

GDF-9 and BMP-15

Answer 6

Intraovarian signals that stimulate the growth of the primordial follicle

Question 7

Primary Follicle

Answer 7

Formed when primordial follicle leaves the proliferating pool, is surrounded by the zona glomerulosa, and the granulosa cells become cuboidal

Question 8

Preantral follicle

Answer 8

• Oocyte becomes surrounded by basal lamina and layer of thecal cells
• ZP receptors are expressed
• Granulosa cells proliferate, release paracrine factors, and become respondent to FSH and testosterone
• Release of angiogenesis factors
  
  • HOWEVER, granulosa remains avascular until post-ovulation

Question 9

Factors that promote atresia

Answer 9

TNF-a, IL-6, & androgens

• Affects granulosa cells and oocytes; thecal cells are recycled
• FSH PREVENTS atresia

Question 10

Antral Follicles

Answer 10

Characterized by stratified granulosa cells and a fluid-filled antrum

• Early follicles become respondent to FSH and thecal cells become respondent to LH
• Inhibin B is also formed

Question 11

Mural Cells

Answer 11

Layer of granulosa cells in the antral follicle that are in close contact w/ the thecal layer; becomes the corpus luteum

Question 12

Cumulus Cells

Answer 12

Layer of granulosa cells in the antral follicle that are adjacent to the oocyte and communicate w/ each other via gap jnxns

=> Released w/ the oocyte during ovulation and facilitates occyte capture by the ciliated fallopian tubes

Question 13

E1

Answer 13

Principal post-menopausal androgen

Question 14

Dominant Follicle

Answer 14

Selected in the early follicular phase; attains dominance later

*Presence indicated by high levels of circulating E2

Question 15

FSH role in selecting dominant follicle

Answer 15

Stimulates granulosa cell proliferation, E2 synthesis, FSH and LH receptor synthesis

*Also negatively feedbacks to the hypothalamus to decrease secretion of GnRH

Question 16

How does the dominant follicle grow w/ decreasing FSH levels?

Answer 16

1. Becomes more sensitive to FSH (increased receptors)
2. Produces IGF-1
3. Increased LH receptors
4. Accumulation of FSH in the antrum

Question 17

Stigma

Answer 17

Poorly vascularized bundle formed when the antrum swells against the surface of the ovary

*Cumulus cells will also separate from mural cells and secrete shit

Question 18

Ovulation (Follicular action)

Answer 18

Proteolytic enzymes produced from LH response breakdown the stigma and the thecal layer gently releasing the cumulus cells and oocyte

Question 19

LH actions on the preovulatory follicle

Answer 19

1. Induces production of metalloproteinases and inflammatory cytokines
2. Induces COX-2 expression (prostaglandin synthesis)
   * COX-2 inhibitors can prevent ovulation
3. Resumes meiosis until Metaphase II
4. Suppresses aromastase
5. Promotes the formation of the corpus luteum

Question 20

Granulosa-lutein cells

Answer 20

*Become vascularized when LH induces VEGF secretion and breakdown of the basil lamina

=> Can now synthesize progesterone from LDL precursors

*Still require theca-lutein cells to produce androgen precursors if granulosa-lutein cells wanna make estrogen

Question 21

Luteolysis

Answer 21

Peak progesterone levels are reach @ Day 8 of the luteal phase; luteum will then start degenerating due to decreased FSH and LH

*Decreased FSH and LH due to the negative feedback of progesterone and E2

Question 22

Proliferative Phase

Answer 22

Increased estradiol regenerates the endometrial lining by:

• Increasing the proliferation of epithelial and stromal cells
• Inducing growth of uterine glands
• Coiling of the spiral arteries
• Increasing progesterone receptors

Question 23

Secretory Phase

Answer 23

Progesterone promotes the differentiation of the endometrium and increases its secretory capacity

• Increasing the permeability of the spiral arteries making the tissue edematous
• Theses changes prepare the endometrium for implantation

Question 24

PGF2a

Answer 24

Induces vasospasms during the menstrual phase causing ischemia and necrosis of the endometrial tissue

=>Will also produce the uterine contractions that expel the desquamated tissue

Question 25

E2 extra-reproductive actions

Answer 25

• Stimulate blood flow to the uterus
• Decrease the viscosity of cervical mucous
• Stimulate binding protein synthesis
• Prevent atherosclerosis
• Inhibit bone resorption

Question 26

Menopause

Answer 26

H-Hot flashes (mediated by increased GnRH)

A-trophy of

V-agina

O-steoporosis

C-oronary artery disease

*Also causes increased GnRH, FSH, and LH

Question 27

Fate of most maturing follicles

Answer 27

Atresia

Question 28

Layers of the uterine wall

Answer 28

Serosa/Adventitia, myometrium, endometrium