Female Reproductive System Flashcards
What does the female reproductive system consist of
Pair of ovaries
Uterus
Fallopian tube
Vulva
Vagina
Explain the function of each part of the system
Ovaries - release ova / eggs into Fallopian tubes; secrete oestrogen
Fallopian tube - carries eggs & leads from each ovary into uterus
Uterus - muscular structure in which foetus develops
Cervix - forms neck of uterus
Vagina - canal where sperm is deposited; acts as birth canal
Rectum - muscular structure of alimentary canal
Anus - opening of alimentary canal that allows faeces out
Vulva - external genitalia
What do the ovaries contain
Primary follicles which have germinal epithelium which produces ova by meiosis
- Produce oestrogen and progesterone
What happens at puberty to secondary sex characteristics
( Caused by oestrogen and progesterone )
- Breast devel
- Pubic hair
- Fat accumulation
- Enlarged pelvic girdle hence wider hips
- Onset of menstruation
- Hair growth under the arms
What is the Fallopian tubes lined with
Cilia which assist in moving the ovum towards uterus
What happens at the fallopian tubes
- Convey the ovum/zygote to the uterus by cilia and muscular contractions
- Are the site of fertilisation
- Are a pathway for the sperm to swim to the ovum
Explain spermatogenesis
- Diploid germinal epithelial cells which line the seminiferous tubules in the tests undergoes mitosis to produce diploid spermatogonia
- These then undergo meiosis to form spermatozoa
- Cells of the sertoli support sperm cells while they develop
Explain oogenesis
Diploid cells in the germinal epithelium of the ovaries form primary follicles.
Within a follicle, one diploid cell undergoes meiosis to form ONE ovum and 3 polar bodies contained within a Graafian Folicle
What is gametogenesis
The process of gamete formation which commences at puberty
Controlled by sex hormones
What makes up the menstrual cycle
The ovarian and uterine cycles
Explain the uterine and ovarian cycle fully
Ovarian - all the processes that occur in the ovary
Uterine - all the processes that occur in the uterus
Explain the menstrual cycle fully
1) Pituitary gland starts secreting FSH
- which stimulates a folic in the ovary to start developing
2) Developing follicle secretes oestrogen and as it enlarges it produces more oestrogen so the levels in the blood incr
3) Oestrogen causes a new endometrium to start developing in the uterus
4) Incr oestrogen levels inhibit FSH secretion by the pituitary gland ( neg. feedback)
5) High oestrogen levels cause pituitary to release high levels of LH ( Day 14)
6) High LH = ovulation
7) High LH cause development of corpus lute from the remains of Graafian follicle in ovary
8) CL secretes incr levels of progesterone causing further thickening of endometrium
9) Incr prog. levels inhibit FSH & LH secretion ( neg feedback)
10) I f fertilisation occurs, CL persists and continues to secrete prog. to maintain endometrium
11) No fertilisation = CL degenerates and so do prog levels
12)
Explain the role of oestrogen fully
- Responsible for secondary sexual characteristics in females during puberty
- Repairs and builds endometrium
- High levels stimulate LH secretion
- Incr movement of cilia in Fallopian tubes too propel ovum towards uterus
Explain the role of progesterone fully
- Promotes further thickening of endometrium
- Prepares endom. for implantation of blastula
- Maintains thickening of endometrium through the entire gestation period
What is fertilisation
When the sperm nucleus fuses with the ovum nucleus to produce a diploid zygote
Explain pregnancy and gestation fully
Pregnancy - all the changes that take place
Gestation - the period development of the foetus in the uterus
Explain the chorion fully
- Outermost membrane which forms a large number of villi
- most = degenerate leaving only those that are embedded in the uterine tissue - Area where villi remain embedded is known as the placenta
- Villi create LSA for exchange of substances
What is the function of the chorion
form the placenta
Explain the amnion fully
- Surrounds the embryo except for the abdominal surface
- Forms a sac containing fluid which bathes the embryo and cushions it from bumps
- supports foetus; holds urine and protects against temp change
Explain the placenta structure fully
- Disc shaped organ, richly supplied with blood vessels
- Consists partly of maternal, partly foetal tissue
- Chorionic villi ( from foetal side) develop endometrium
Foetal and maternal blood do not mix - seperated by semi permeable membrane of chorionic villi
Explain the placenta functions fully
Allows for :
- Diffusion of O2 and nutrients from maternal side to foetal capillaries
- Diffusion of CO2 and urea from foetal capillaries to maternal blood
- Passive immunity - maternal antibodies pass into foetal blood
- Acts as a micro filter-barrier preventing most pathogens and some drugs from passing to the foetus
- Serves as an endocrine organ - secreting progesterone to maintain pregnancy / prevent miscarriage
