Menstruation and Ovulation Flashcards
Name the two phases of Ovulation and the length of each
Follicular phase - 14 days average (but changes person to person)
Luteal phase - 14 days (fixed)
What happens in the follicular phase
Menstruation Increase in LH, FSH and Oestrogen Increase in FSH and LH triggers: completion of 1st meiotic division to form secondary follicle Oestrogen: Stimulates thickening of endometrium Thinning of cervical mucus
In the follicular phase LH and FSH do what?
Increase in FSH and LH triggers: completion of 1st meiotic division to form secondary follicle LH surge (triggered by oestrogen/positive feedback) - causes ovulation
In the follicular phase what is the role of oestrogen?
Stimulates thickening of endometrium
Thinning of cervical mucus
Switches control of LH and FSH to positive feedback
What triggers ovulation
LH surge
12-36 hours after surge ovulation occurs
During which phase does ovulation occur?
Follicular
How long does the luteal phase last?
14 days
Describe the hormonal changes in the luteal phase
LH, FSH and oestrogen fall
Increase in the production of progesterone
What is progesterone produced by?
Corpus Luteum (which develops from leftover follicular cells)
What happens in the follicular phase if fertilisation doesn’t occur?
Corpus luteum degenerates and reduction in progesterone which triggers menstruation
What happens in the follicular phase if fertilisation occurs?
Embryo produces hCG which stimulates maintenance of corpus luteum and therefore maintenance of a viable endometrium
Describe a normal menstrual cycle
21-35 days
Menstruation lasting 4-6 days
No inter-menstrual bleeding/post-coital bleeding
No passage of excessive amounts of blood/clots
Define Menorrhagia
Prolonged heavy bleeding - loss of >80mls
Define Dysmenorrhea
Painful periods
Define Polymenorrhea
Menstrual cycle lasting <21 days
Define Oligomenorrhea
Cycle lasting >35 days
Define Amenorrhea
Absence of period >6 months (can be primary or secondary)
List causes of Primary amenorrhea (5)
Imperforate hymen
Turners syndrome 45XO
Testicular feminization (female phenotype, male genotype)
Anorexia, excessive exercise
Define primary amenorrhea
Failure to start periods by age 16
List causes of secondary amenorrhea (6)
Pregnancy
Menopause
Polycystic Ovarian Syndrome
Drug induced: withdrawal from contraception, steroids, recreational drug use
Genetic disorders: Kallmans syndrome, Turners syndrome, Prader Willi
Systemic disease: thyroid dysfunction, renal railure, pituitary disease and haemochromatosis
Define secondary amenorrhea
Loss of menstruation for 6 months after periods were previously established
