Female Reproductive Physiology Flashcards
The ovaries contain the ovarian ________, which in a cyclical fashion undergo _______ and release a mature egg every menstrual cycle
follicles
oogenesis
what is oogenesis?
production of an egg
Egg implants into the ______
uterus
what are the 2 parts of the uterus?
Uterus has 2 parts which are the body and the cervix
what are the different areas of a ovary?
surface
cortex
medulla
what is the structure of the surface of an ovary?
connective tissue capsule covered with a layer of simple cuboidal epithelium
what is the structure of the cortex of a ovary?
peripheral part, connective tissue containing ovarian follicles (one oocyte surrounded by single layer of cells)
what is the structure of a medulla of a ovary?
central part, connective tissue with blood cells
1
medulla (contains neurovascular structures)
2
cortex (contains ovarian follicles)
3
cuboidal epithelium
what is the function of the ovaries?
- Oocyte production:
- One mature egg per menstrual cycle, around 400 ovulated during entire reproductive lifespan
- Majority of eggs perish during the cycle
- Finite number, declines with increasing age
- Steroid hormone production:
- Oestrogen develops female secondary sexual characters
- Progesterone prepares endometrium for implantation
- 50% of testosterone produced by ovaries before menopause
what is oogenesis?
differentiation of the ovum (egg cell) into a cell competent to further develop when fertilized
what is the process of oogenesis?
- Primordial germ cell mitosis in foetal life only and primordial follicles arrested in the stage of first melotic division until puberty
- First melotic division complete and second division starts after puberty and leads to the release of one secondary oocyte in a menstrual cycle which is capable of fertilisation
- Second melotic division completes after fertilisation of oocyte with sperm
what are the follicular development stages?
- Primordial follicles – primary oocyte arrested in first meiotic division surrounded by one layer of squamous pre-granulosa cells
- Primary follicle – oocyte surrounded by zona and cuboidal granulosa cells
- Secondary follicles – increased oocyte diameter and multiple layer of granulosa cells, resumption of first meiotic division
- Tertiary/graffian follicle – follicular fluid between the cells which coalesce to form antrum, completion of first meiotic division to form secondary oocyte and start of second meiotic division
Pictures hsowing Chromosomal division during oogenesis
Endocrine control of female reproductive axis – Hypo_______-_______-_______ axis
Hypothalamic-pituitary-ovarian axis
- The function of the ovaries are controlled and coordinated by ________
hormones
The function of the ovaries are controlled and coordinated by hormones
what hormones and where are they from?
Starts at the hypothalamus in the brain and this released GnRH (gonadotropin releasing hormone) which then acts on the anterior pituitary gland causing it to release FSH (follicle stimulating hormone) and LH (Luteinizing hormone)
LH and FSH cause the ovaries to release what hormones?
LH and FSH cause the ovaries to release oestrogen and progesterone which are steroid hormones that act on the uterus to coordinate the menstrual cycle
what feedback is present in the Hypothalamic-pituitary-ovarian axis?
- Negative feedback is important to keep the hormone levels stable to make sure the menstrual and ovarian cycles are coordinated within one month
- Oestrogen on days 12-14 causes positive feedback to help ovulation
describe the ovarian cycle?
Due to the positive feedback of oestrogen there is a peak of LH which results in ovulation (release of egg)
what are the different stages in the ovarian cycle?
the follicular phase and the luteal phase
what happens in the follicular phase?
Only one dominant follicle will develop in the follicular phase
what happens in the luteal phase?
what are the effects of oestrogen and progesterone on the endometrium?
Oestrogen causes thickening of the endometrium and progesterone causes changes in the vasculature of the endometrium and also adds thickness
Reaches max thickness at day 28 in time for pregnancy and if this doesn’t happen then it breaks down and hormones decrease
Ovarian and menstrual cycle interplay:
Oestrogen is dominant in the ________ phase and progesterone is dominant in the _____ phase
follicular
luteal
Summary picture: showing the ovarian and mestraul cycle all together
Case Study – Female Reproductive Physiology
what is Amenorrhoea?
no periods
what is primary and seconday Amenorrhoea?
Primary – never had a period
Secondary – stop to bleed for 6 months or more sometime in their lives
what causes Amenorrhoea
- Problem with regulating hormones
- Problem with ovarian function
- Problem with uterus or outflow tract
Amenorrhoea can be cause by problems with regulating hormones, what things would cause this?
- Hypothalamic or pituitary cause – hypogonadotropic hypogonadism (low FSH, LH, high prolactin)
- Function – excessive weight loss or gain, over exercising, stress (once any of these are fixed periods will return)
- Chronic medical conditions – diabetes, sarcoidosis, renal disease, TB
- Intracranial space occupying lesion – prolactinoma, tumours, cysts
- Infection or trauma – meningitis, intracranial bleed, Sheehans
- Drugs – glucocorticoids, anabolic steroids, opiates
- Genetic – Kallmanns syndrome
Amenorrhoea can be cause by problem with ovarian functions, what things would cause this?
Hypergonadotropic hypogonadism – high or normal FSH, LHJ
- Genetic – turners syndrome (46X), fragile X
- Ageing – steep decline in ovarian function past 35 years
- POI (primary ovarian insufficiency) or POF (primary ovarian failure)
- Chronic illness – autoimmune diseases
- Radiotherapy or chemotherapy
- Infection – tuberculosis, mumps oophoritis (inflammation of ovary)
Amenorrhoea can be cause by problems with uterus or outflow tract, this can be congenital or iatrogenic
what are some congenital causes?
- Absent uterus, vagina – lack of Mullerian duct development (MRKH syndrome)
- Transverse vaginal septum or imperforate hymen – Mullarian duct fail to canalise
- Androgen insensitivity syndrome
Amenorrhoea can be cause by problems with uterus or outflow tract, this can be congenital or iatrogenic
what are some iatrogenic causes?
- Uterine adhesions or synechiae (asherman syndrome)
- Radiotherapy – pelvic or cervical
what is the management of amenorrhoea?
- Life style changes
- Optimise control of medical illness
- Stop drugs or switch to alternatives
- Prolactinoma- medical treatment
- Intracranial SOL- surgical treatment
- Vaginal anomalies (septum or hymen)- surgical treatment
- Uterine adhesions- surgical division hysteroscopic
- Fertility preservation before radiotherapy and chemotherapy
- Fertility treatment- IVF with own or donor eggs
