Test 1 Menstrual Cycle

Question 1

Hypothalamic-Pituitary-Gonadal Axis

Answer 1

• Hypothalamus release GnRH which
  
  • stimulates Anterior Ptituitary to release LH and FSH.
    
    • LH stimulates Theca Cells (androgens)
    • FSH stimulates granulosa Cells (progestins and estrogens)
• Once dominant follicle is chosen, the granulosa cells will get LH receptors
• Estrogens and progestins feed back to the hypothalamus (negative feedback)
• At some point in the cycle, it becomes positive feedback
• FSH and LH surge causing ovulation

Question 2

Ovarian cycle

Answer 2

• changing patterns of hormone production and secretion→ what is happening in the ovaries
  
  • Follicular Phase
  • Ovulation
  • Luteal Phase

Question 3

Follicular Phase

Answer 3

• Part of Ovarian cycle
• Follicular phase – 10 – 17 days on average in most women
  
  • GnRH pulse every 60 – 90 minutes
  • Ovary
  • Estrogen increases
  • Dominant follicle chosen – usually the one with the most FSH receptors around day 5 to 7

Question 4

Ovulation

Answer 4

• Part of Ovarian Cycle
• Ovulation – around day 14
  
  • Surge of FSH and LH

Question 5

Luteal Phase

Answer 5

• Part of Ovarian Cycle
• Luteal phase
  • Ovary
  • Corpus luteum produces progesterone
  • Progesterone peaks about 7 – 8 days after ovulation – when implantation is likely to occur
  • If pregnancy occurs, Hcg is secreted à keeps the corpus luteum around to produce progesterone until the placenta develops and makes the progesterone
  • If pregnancy does not occur, corpus luteum demises and progesterone drops→ menstruation

Question 6

Q: Which day is considered the first day of menstruation?

Answer 6

The first day of menses

Question 7

Q: After the ovum has been released, the dominant follicle becomes?

Answer 7

the corpus luteum

Question 8

Endometrial Cycle

Answer 8

• (changes in endometrial morphology and function) – what is happening in the uterus
  
  • Menstrual Phase
  • Proliferative Phase
  • Secretory Phase

Question 9

Menstrual Phase

Answer 9

• Part of Endometrial Cycle
• Menstrual phase
  • Regression of corpus luteum – decrease in progesterone
  • Shedding of endometrium (menstruation) due to progesterone withdrawal

Question 10

Proliferative phase

Answer 10

• Part of Endometrial Cycle
• Proliferative phase
  • Endometrium
  • Endometrial epithelial cell proliferation – due to increase in estrogen
  • Thin, watery cervical mucus – due to increase in estrogen – prepares for ovulation

Question 11

Secretory phase

Answer 11

• Part of Endometrial Cycle
• Secretory phase
  • Endometrium
  • Differentiation of endometrial epithelial cells
  • Elevation of basal body temperature (due to progesterone in luteal phase)

Question 12

Integrated Cycle

Answer 12

• Follicular Phase
• Proliferative Phase
• Ovulation
• Luteal Phase
• Secretory Phase
• Menstrual Phase

Question 13

Integrated Cycle: Follicular

Answer 13

• Ovarian
• Follicular phase (~10-17 days)
  
  • FSH stimulates proliferation of granulosa cells, which convert androgens (from theca cells) into estrogen

Question 14

Integrated Cycle: Proliferative

Answer 14

• Endometrial
• Proliferative phase
  • Preparing the endometrium for implantation
  • Estrogen causes endometrial epithelial cell proliferation, up-regulation of estrogen and progestin receptors, and increased production of thin, watery cervical mucus

Question 15

Integrated Cycle: Ovulation

Answer 15

• Ovarian
• Ovulation (~day 14)
  • Once estrogen reaches a critical level for 2-3 days, positive feedback occurs to the anterior pituitary, resulting in FSH and LH surges
  • Gonadotropin surge causes ovulation (follicular wall ruptures and releases oocyte about 30 hours after surge)
  • Oocyte travels to fallopian tube for fertilization

Question 16

Q: After the ovum has been released, the follicle becomes?

Answer 16

the corpus luteum

Question 17

Integrated Cycle: Luteal

Answer 17

• Ovarian
• Luteal phase (~14 days)
  
  • Granulosa and theca cells take up steroids and lutein pigment to become the corpus luteum
  • Corpus luteum produces progesterone (and estrogen and androgen), which suppresses new follicular growth

Question 18

Integrated Cycle: Secretory

Answer 18

• Endometrial
• Secretory phase
  • Progesterone causes differentiation of endometrial epithelial cells into secretory cells and elevation in basal body temperature

Question 19

Integrated Cycle: Menstrual

Answer 19

• Endometrial
• Menstrual phase
  • Regression of corpus luteum and resulting decrease in progesterone and estrogen levels results in shedding of the endometrium and menstrual flow
  • Decreasing estrogen levels stimulate GnRH, FSH, and LH, which stimulate ovaries to produce more estrogen, which stops blood flow by inducing clot formation and regrowth of the endometrium

Question 20

In normal menses the number of cycles a women has is

Answer 20

400 – 500 from menarche to menopause

Question 21

In normal menses the frequency of cycles is

Answer 21

Every 21 – 35 days

Question 22

In normal menses the duration of menses lasts

Answer 22

4 – 6 days

Question 23

In normal menses the amount of blood loss is approximately

Answer 23

20 – 80 mL

Question 24

In normal menses a woman loses how much iron per cycle

Answer 24

• 13 – 16 mg
  
  • Women of child-bearing age are typically iron deficient atresia

Question 25

Summarize the release of hormones fthrough the HPA axis

Answer 25

• Hypothalamus → GnRH→ anterior pituitary→ FSH/LH→ ovaries→ ovarian steroids
  
  • Pulses and changes in feedback are important

Question 26

How do the ovarian and endometrial cycles relate?

Answer 26

They occur simultaneously