MENSTRUAL CYCLE Flashcards
What is the average length of the menstrual cycle?
28 days
What do we call the first period of a girl’s life?
Menarche
What are the three phases of the ovarian cycle and how long is each?
Follicular phase - first 13/14 days
Ovulation
Luteal phase - latter 13/14 days
What happens in the ovaries during the first 14 days of the menstrual cycle (the follicular phase)?
Development of several primordial follicles into in the end a single, selected tertiary follicle which will then expel the ovum so that it can escape the ovaries during ovulation. The structure left behind is called the corpus luteum.
What happens in the ovaries during the latter 14 days of the menstrual cycle (the luteal phase)?
The corpus luteum (the structure left behind by the ovum) release progesterone and oestrogen before being slowly broken down into first the corpus albicans before being fully degraded.
What are the three phases of the uterine cycle and how long is each?
Menses - first 7 days
Proliferative stage - days 7-14
Secretory phase - Latter 14 days
What is happening to the uterus during menses of the menstrual cycle?
There is a breakdown of the uterus endometrium.
What is happening to the uterus during the proliferative phase of the menstrual cycle?
The endometrium is built up/thickened to be ready for implantation.
What is happening to the uterus during the secretory phase of the menstrual cycle?
The endometrium is maintained whilst the corpus luteum is continuously secreting hormones, before both structures begin to break down and eventually menses starts.
What are the two pituitary hormones involved in the menstrual cycle?
Follicular stimulating hormone (FSH)
Luteinizing hormone (LH)
What are the two ovarian hormones involved in the menstrual cycle?
Oestrogen
Progesterone
What is the hormone that is at its highest during the first week of the menstrual cycle and is responsible for initiating the follicular phase of the ovarian menstrual cycle?
Follicular stimulating hormone (FSH)
What is the hormone that has a small rise around day 3 or 4 of the menstrual cycle which initiates the release of another hormone during this phase?
Oestrogen which initiates the release of luteinizing hormone (LH)
What is the hormone largely responsible for the release of the oocyte in ovulation by having a sudden rise in concentration on about day 13?
Luteinizing hormone (LH)
What is the hormone responsible for the proliferative stage of the uterine cycle?
Oestrogen
What is the hormone produced by the corpus luteum?
Progesterone
What are the hormones responsible for the maintenance of the endometrium in the secretory phase of the uterine cycle?
Progesterone and oestrogen
What causes the breakdown of the endometrium and hence the beginning of the menses and the cycle?
The degradation of the corpus luteum means that levels of progesterone decrease bit by bit and eventually the endometrium can no longer be maintained.
What stimulates the release of FSH to start the follicular phase of the ovarian cycle?
Low levels of progesterone and oestrogen.
How is the endometrium maintained in pregnancy?
The implanted embryo will produce human chorionic gonadotrophin which acts to maintain the corpus luteum in the same way as LH and FSH.
What is the average age of menarche in the UK?
12.9 years
How short and long can the menstrual cycle be without being considered abnormal?
21-45 in young women
21-31 in older adults
What are the symptoms that have been reported during menses and the preceding two weeks?
Pain Acne Tender breasts Bloating Feeling tired
What are the symptoms of premenstrual syndrome (PMS)?
Stress Anxiety Insomnia Headache Fatigue Increased mood swings Emotional sensitivity Changes in libido
How do we treat premenstrual syndrome (PMS)?
Normally COCP unless contraception is an undesired effect
