Test 1 Menstrual Cycle Flashcards Preview

2016 Endocrine > Test 1 Menstrual Cycle > Flashcards

Flashcards in Test 1 Menstrual Cycle Deck (26)
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1
Q

Hypothalamic-Pituitary-Gonadal Axis

A
  • 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
2
Q

Ovarian cycle

A
  • changing patterns of hormone production and secretion→ what is happening in the ovaries
    • Follicular Phase
    • Ovulation
    • Luteal Phase
3
Q

Follicular Phase

A
  • 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
4
Q

Ovulation

A
  • Part of Ovarian Cycle
  • Ovulation – around day 14
    • Surge of FSH and LH
5
Q

Luteal Phase

A
  • 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
6
Q

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

A

The first day of menses

7
Q

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

A

the corpus luteum

8
Q

Endometrial Cycle

A
  • (changes in endometrial morphology and function) – what is happening in the uterus
    • Menstrual Phase
    • Proliferative Phase
    • Secretory Phase
9
Q

Menstrual Phase

A
  • Part of Endometrial Cycle
  • Menstrual phase
    • Regression of corpus luteum – decrease in progesterone
    • Shedding of endometrium (menstruation) due to progesterone withdrawal
10
Q

Proliferative phase

A
  • 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
11
Q

Secretory phase

A
  • Part of Endometrial Cycle
  • Secretory phase
    • Endometrium
    • Differentiation of endometrial epithelial cells
    • Elevation of basal body temperature (due to progesterone in luteal phase)
12
Q

Integrated Cycle

A
  • Follicular Phase
  • Proliferative Phase
  • Ovulation
  • Luteal Phase
  • Secretory Phase
  • Menstrual Phase
13
Q

Integrated Cycle: Follicular

A
  • Ovarian
  • Follicular phase (~10-17 days)
    • FSH stimulates proliferation of granulosa cells, which convert androgens (from theca cells) into estrogen
14
Q

Integrated Cycle: Proliferative

A
  • 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
15
Q

Integrated Cycle: Ovulation

A
  • 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
16
Q

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

A

the corpus luteum

17
Q

Integrated Cycle: Luteal

A
  • 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
18
Q

Integrated Cycle: Secretory

A
  • Endometrial
  • Secretory phase
    • Progesterone causes differentiation of endometrial epithelial cells into secretory cells and elevation in basal body temperature
19
Q

Integrated Cycle: Menstrual

A
  • 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
20
Q

In normal menses the number of cycles a women has is

A

400 – 500 from menarche to menopause

21
Q

In normal menses the frequency of cycles is

A

Every 21 – 35 days

22
Q

In normal menses the duration of menses lasts

A

4 – 6 days

23
Q

In normal menses the amount of blood loss is approximately

A

20 – 80 mL

24
Q

In normal menses a woman loses how much iron per cycle

A
  • 13 – 16 mg
    • Women of child-bearing age are typically iron deficient atresia
25
Q

Summarize the release of hormones fthrough the HPA axis

A
  • Hypothalamus → GnRH→ anterior pituitary→ FSH/LH→ ovaries→ ovarian steroids
    • Pulses and changes in feedback are important
26
Q

How do the ovarian and endometrial cycles relate?

A

They occur simultaneously