Menstrual Cycle Flashcards
1
Q
Normal menstrual cycle
A
Menarche <16 yrs Menopause >45 yrs Bleeding <8days Blood loss <80ml Cycle length 23-35 days
2
Q
Day 1-4 (3-7days)
A
Menstruation - decrease in progesterone + uterine contractions –> shed endometrium
3
Q
Day 5-13 (proliferative phase)
A
Proliferative stage
GnRH released by hypothalamus –> FSH and LH by anterior pituitary –> follicular growth
Maturing follicles produce oestradiol –>
- -ve feedback to AP - ensures maturation of single follicle
- +ve feedback –> LH surge –> ovulation occurs 36 hours later
- Reformation and thickening of endometrium
4
Q
Irregular periods
A
Periods outside the range of 23-35 days
5
Q
Day 14-28 (luteal/secretory phase)
A
Follicle now becomes the corpus luteum –> oestrodiol and progesterone –> ‘secretory changes in endometrium (cells enlarge, glands swell and BF increases)
Corpus luteum begins to fail if egg his not fertilised –> hormone levels fall and endometrium breaks down
