menstrual cycle Flashcards
female reproductive cycle
what 2 things characterise menarche in the female reproductive lifecycle and what is the average age it occurs?
Think uterine bleed and what it is in response to and think HPO axis
- first ovarian-controlled uterine bleed in response to increased levels of oestrogen (Periods)
- also represents maturation of HPO axis
- average age this occurs is 13 years old
female reproductive lifecycle
what is the mean age of menopause?
51.5 years
female reproductive lifecycle
what are 5 features of the ovarian cycle?
Think ovulations, ovum and endocrine regulation, primordial follicle, the phases of the ovarian cycle and folliculogenesis
- intervals between successive ovulations
- displays ovum maturation and release under endocrine regulation
- progression of a primordial follicle to the corpus luteum
- comprises of follicular phase (1-14 days) all the way to the luteal phase (12-28 days)
- shows folliculogenesis
reproductive cycles
what 5 things happen/is shown in the uterine cycle?
think hormones on uterus, what the endometrium is doing in the cycle, think phases of uterine cycle, think blood vessels, think proliferation of blood vessels
- effects of ovarian hormones on uterus
- endometrium is central tissue degenerating and regenerating
- proliferative phase –> secretory phase
- vascular function
- angiogenesis
reproductive hormones in the female reproductive tract
name the 6 hormones involved in the female reproductive tract
- oestradiol-17b
- progesterone
- FSH
- LH
- Inhibins
- Anti-mullerian hormone (AMH)
actions of sex steroids
what 6 things oestrogens do
think reproductive, muscloskeletal vascular and CNS, think GnRH secretion, think endometrium regrowth, think endometrium for progesterone, secondary female sex characteristics, think breast tissue
- effects: on reproductive,muscloskeletal,vascular and central nervous system
- regulates GnRH secretion
- stimulates proliferation of endometrium
- prepare endometrium for proliferation of endometrium
- stimulates secondary characteristics of the female
- stimulate ductal growth of breast tissue
actions of the sex steroids
what are 6 things that progesterone does in the body
think GnRH, think endometrium and implantation and deciduslisation, think uterus, think breast tissue, think oestrogen
- regulates GnRH secretion
- prepare endometrium for implantation
- stimulate decidualisation of endometrium
- maintains uterus during pregnancy
- stimulates growth (alveolar) of breast tissue
- synergistic and opposing effects to oestrogen
idealised menstrual cycle
what is the order of the idealised menstrual cycle and what days are the bleeding and ovulation phases
- Bleeding (Day 1-7)
- Proliferative (follicular)
- ovulation (Day 13-15)
- secretory (luteal)
- implantation (if sperm reaches egg) –> pregnancy
phases of the menstrual cycle
what hormone dominates the proliferative phase and what hormone dominates the secretory phase of menstrual cycle
- proliferative: oestrogen
- secretory: progesterone
phases of the menstrual cycle
which phase of the menstrual cycle is variable and why does the secretory phase last 14 days
the proliferative phase
- secretory phase lasts 14 days because corpus luteum only survives for 14 days
hormone levels in menstrual cycle
outline hormone levels of Oestrogen, Progesterone, LH and FSH from Day 1 of menstrual cycle
For stage 1, think what happens to FSH and LH levels and why.
For stage 2, think what FSH and LH do and what this does to levels of another hormone.
For stage 3, think what oestrogen does, the day it peaks and what it causes to the levels of LH and why it is effected
For stage 4, think about what now happens to LH and FSH levels and what happens to progesterone levels and why
For stage 5, think what happens to progesterone and oestrogen levels if implantation does not occur
- FSH and LH slightly rise because of lack of oestrogen and progesterone so no negative feedback
- FSH and LH rising stimulate follicles in ovaries to produce Oestrogen, causing an oestrogen spike.
- Oestrogen promotes endometrial proliferation, with peak at day 12-14, and also causes LH peak due to positive feedback as LH needs to be maximum prior to ovulation.
- LH and FSH levels then fall rapidly, and there is a progesterone peak to allow thickening of endometrium to prepare the endometrium for implantation.
- if implantation does not occur, progesterone and oestrogen levels fall.
hormone levels in menstrual cycle
what is the function of inhibins in the menstrual cycle
to inhibit the growth of other follicles
endometrial structure and histology
what type of tissue is the endometrium and what has it got in it
glandular tissue with extensive stroma
endometrial stucture
what is the window of implantation
Think blastocyst
- time period when endometrium is optimally receptive to blastocyst
pinopodes
what are the markers of endometrial receptivity called and what do they do
- pinopodes
- attract blastocyst to endometrium