Menstruation Overview

Question 1

What is the hormonal feedback of the menstrual cycle? 3 steps

Answer 1

1. Hypothalamus –> GNRH
2. Pituitary –> FSH, LH
3. Gonads –> estrogen, progesterone

Question 2

What does the menstrual function depend on?

Answer 2

pulsatile secretions of GnRH in a critical frequency and concentration
- beginning: every 60-90 minutes
- At the end: every 3-4 hours

Question 3

What happens if there is a continuous GnRH release?

Answer 3

There would be an inhibitory effect of the production of gonadal hormones
- abnormalities in secretion rates can result in poor fertility and amenorrhea

Question 4

Explain the follicular development phase. What causes inc release of FSH release

Answer 4

1. Decreasing estrogen levels –> inc in FSH secretion
2. Follicular growth begins

This phase can vary

Question 5

What occurs in the ovaries during follicular development

Answer 5

• FSH induces androgen –> estrogen which rises estradiol levels
• Rising estradiol –> surpress FSH –> LH rise
• HIGH ESTRADIOL (>200 pg/mL for >50 hours) causes LH surge - CRITICAL FOR OVULATION TIMING

Falling FSH = dominant follicle observable

Question 6

What occurs in the follicular phase in the uterus?

Answer 6

Endometrial shedding
- falling progesterone levels causes endometrial lining to slough (2-7 days)

Endometrial development
- As estrogen rizes –> thicker + more glands + vascularized endometrium

Question 7

Explain when the ovulation phase occurs

Answer 7

24-36 hours after estradiol peak
10-12 hours after LH peak

Question 8

What occurs during the ovulation phase? How long does the sperm and ovum survive for?

Answer 8

• Progesterone enhances proteolytic enzymes, along with prostaglandins –> causes rupture of the follicular wall
• estrogen rise –> rise in FSH –> which releases the oocyte from the follicle
• Ovary wall ruptures –> release secondary oocyte (some women can feel pain upon ovulation = mittleshmerz)
• Sperm survives up to 5 days; Ovum survives for 12-24 hours

Question 9

Explain what occurs in the OVARY during the luteal phase if conception occurs?

Answer 9

• Corpus luteum continues to secrete estrogen, progesterone and androgen
• Progesterone RISES SHARPLY after ovulation to prevent new follicle

Question 10

Explain what occurs in the ovary during the luteal phase if conception does NOT occurs?

Answer 10

Corpus leteum regresses 9-11 days after ovulation
- progesterone/estrogen levels decrease –> FSH increase –> begins new follicle development

Question 11

Explain what occurs in the UTERUS during the luteal phase if conception occurs?

Answer 11

Implantation
- Progesterone makes endometrial cells become secretory
- Endometrium thickens, covered in thick mucus layer (to support implantation)

Fertilized egg secretes hCG which prevents luteal regression

Question 12

When does HCG appear? What is its purpose? How long is it functional for?

Answer 12

Appears 9-13 days after ovulation

Purpose: prevents luteal regression –> maintains progesterone release

Maintains progesterone until 6-8 weeks
- placenta takes over progesterone production

Question 13

When should you conceive if your cycle is 31 days

Answer 13

31-14 = 17 days
+/- 2 days before that

Question 14

Explain urinary LH ovulation kit method

Answer 14

Start 4 days before expected ovulation date
- monitor levels daily

Question 15

Explain change in cervical mucous method

Answer 15

observe cervical mucous watery + increased discharge = ovulation

Question 16

Explain basal body temperature method

Answer 16

BBT drops 1 day before ovulation and rises after ovulation

Monitor BBT daily, establish avg temp look for drop 1 day before ovulation

Question 17

Explain transvaginal ultrasound method

Answer 17

Ultrasound
- look for reduced follicle size corpus luteum formation

Question 18

Explain salivary ferning method

Answer 18

Microscope look for fern leaves in saliva
- crystallization = fertile