Female Reproductive system Flashcards
Whats the function of the female reproductive system?
- Formation of eggs
- Reception of sperm
- Provision of suitable environment for fertilisation and foetal development
- Childbirth (parturition)
- Lactation
What are ovaries?
- Produces female sex hormones & ova (eggs)
- Contains ovarian follicles in various stages of maturity
What are follopian tubes?
- Fallopian tubes or oviducts are the first of 3 organs that form the female duct system
- Connect ovaries to uterus
- 10 cm long
- Takes 5 days to reach the uterus
What is the uterus?
- In pelvic cavity
- Walls have 3 layers
- Perimetrium
- Myometrium
- Endometrium
- Menstrual cycle prepares uterus to receive, nourish and protect a zygote
State layers of uterine wall
- Perimetrium
- Myometrium
- Endometrium
Whats the myometrium?
- middle layer uterus
- smooth muscle layer; contracts during birth & menstruation
Whats endometrium?
- innermost layer of uterine wall
- simple columnar epithelium and connective tissue.
- Contains glands, arteries & veins which help to nourish the implanted embryo.
- Varies in thickness during the uterine cycle and breaks down / excreted during menstruation
Whats the menstual cycle?
- Collective cyclical changes occurring within ovaries and uterus over approx. 28 days – day 1 is first day of menstrual flow
Difference between ovarian and uterine cycles?
Ovarian - chanfes in maturation of follicles
Uterus - changes in uterus
Whats the menstrual stage?
- Days 1-5
- 50-150mls
- Endometrium lost to basal layer
Whats the proliferation stage?
- Days 4-13
- Growth of endometrium
- Spiral arteries
- Tubular glands
- Vascular mucosa
- Receptor cells primed
WHat day is ovulation?
14
Whats the secretory stage?
- Day 15-28
- Spiral arteries tortuous
- Receptor cells secrete glycogen etc
Whats the degreneration stage?
- No progesterone
- Blood supply cut
- Lysosomes released
- Autodigestive
State the stages of the menstrual cycle
- Menstrual
- Proliferation
- Ovulation
- Secretory
- Degeneration – no progesterone
State the phases of ovarian cycle
- follicular phase
- luteal phase
Whats the follicular phase?
- day 1 until ovulation (day 14 in the 28 day cycle)
- ovarian follicles develop from primordial cells to Graafian follicles due to influence of FSH
- developing follicles release increasing amounts of oestrogen
- increased oestrogen causes sudden increase in LH (LH surge) which stimulates ovulation
Whats the luteal phase?
- day of ovulation (rupture of the follicle to release egg) until day before the menstrual flow begins (day 28)
- LH surge causes development of the corpus luteum & corpus luteum secretes progesterone
- corpus luteum will degenerate 10 days after ovulation if no pregnancy event
What is the uterine cycle?
- changes that occur in the endometrium during the menstrual cycle
- Cycle starts and ends with menstruation
- Menstruation is the shedding of the endometrium
- There are three phases of the uterine cycle:
- Menstrual phase
- Proliferative phase
- Secretory phase
State three phases of uterine cycle
- Menstrual phase
- Proliferative phase
- Secretory phase
Whats the menstual phase?
- Lasts from approx. days 1-5
- Ovarian hormones are at their lowest levels in the cycle
- Functional part of the endometrium breaks down and is sloughed
- Passes out of the body through the cervix & vagina as menstrual flow
Whats the proliferative phase?
- Days 6 (menstrual flow stops) to 14
- Blood vessels & glands that form the endometrium regenerate due to increasing amounts of oestrogen from the developing follicle
Whats the secretory phase?
- Lasts from days 15-28
- Endometrial glands secrete glycogen and vascularisation of the endometrium continues
- Changes are caused by increased progesterone levels by the corpus luteum
- If there is no fertilization, the corpus luteum degenerates towards the end of this phase and progesterone decreases
- Decreasing progesterone thus decreases blood supply to endometrial cells, cells die, the endometrium breaks down and menstrual flow starts again
What are some female reproductive hormones?
- FSH
- LH
- Oestrogen
- Progesterone
What does FSH do?
- From anterior pituitary
- Stimulated by GnRH
- Stimulates maturation of ovarian follicle
- Stimulates production of oestrogen
What does LH do?
- Anterior pituitary
- Stimulus GnRH
- Stimulates production of oestrogen & progesterone
- Stimulate maturation of ovarian follicles; ovulation
Whats oestrogen?
- Sourced in Developing follicles & corpus luteum - After 6 wks. of pregnancy: placenta
- Stimulus – FSH and LH
- Growth & maturation of reproductive organs & breasts; promote proliferative phase of the uterine cycle; facilitate oogenesis; stimulate capacitation of sperm; stimulate growth of uterus and mammary glands in pregnancy
- Promote long bone growth & feminisation of the skeleton; inhibit bone resorption; promote female pattern of fat deposit; female libido, etc.
Whats progesterone?
- Sourced Corpus luteum - After 6 wks. of pregnancy: placenta
- Stimulated by LH
- Facilitates growth of breasts; promotes secretory phase; during pregnancy quiets the myometrium and enhances the ability of mammary glands to produce milk; increases body temperature
What hormones are present during pregnancy?
- Humans chorionic gonadotrophin
- Oestrogen
- Progesterone
- Prolactin
- Relaxing
- Oxytocin
Function of HCG in pregnancy
- Human chorionic gonadotrophin (HCG)
- Acts like luteinising hormone (LH) to maintain corpus luteum (and preventing menstruation), normally corpus luteum atrophies
Function of oestrogen during pregnancy
- Myometrial hypertrophy, external genitalia enlargement
- softening of pelvic ligaments
Function of progesterone during pregnancy
- Proliferation of endometrium, inhibition of uterine contractions, development of alveoli in mammary glands
Function of prolactin in pregnancy
- Milk production when oestrogen falls after parturition.
- Inhibits FSH release and ovulation after parturition
Function of relaxing hormone during pregnancy
- Produced for the flexibility of tissues
Function oxytocin hormone in pregnancy
- For uterine contractions during labour
Developmental stages of fertilisation
- Zygote - fusion of gametes to 8 cells
- Morula - clump of cells undergoing mitosis
- Blastocyst - day 4-20 inner cell mass to bilaminar disc
- Embryo – day 21 to 56 (8 weeks) from somites through organogenesis
- Foetus - week 9 to birth
What is the process of fertilisation?
- The joining or fusion of sperm and ova
- Sperm penetrate the corona radiata and the zona pellucida
- Takes many sperm to release enough enzyme from the acrosome to penetrate the egg
- Depolarisation of the cell membrane of the fertilised egg and release of** calcium ions **to prevent polyspermy
- -the acrosome of a sperm secretes enzymes that digest the zona pellucida of the egg
- -the sperm then **binds to the plasma membrane **of the egg and enters the cell
- -the genetic information of the sperm fuses with the egg nucleus to complete fertilization form zygote
Whats the uterus like during pregnancy?
- Zygote embedded in endometrium
- Nourished by uterine secretions until placenta established
- Placenta secretes progesterone: prevents uterine contractions
- After 40 weeks oestrogen & oxytocin promote uterine contractions
What happens in the Fimbraie?
- Fimbriae have ciliated finger-like projections at the ovarian end but do not touch the ovary
- Cilia on the fimbriae and lining the oviducts beat gently to guide the egg towards the uterus
- After ovulation, the oocyte is moved towards the fimbriae
- Move ovum from ovary to uterus by peristalsis and ciliary movement
Where does fertilisation normally occur?
- Fertilization often takes place in the ampulla
What is follicle maturation stimulated by?
- Follicle maturation stimulated by FSH and oestrogen
What triggers ovulation?
- Ovulation triggered by LH: ovum released every 28 days
Whats polyspermy?
(fertilisation by more than one sperm)