Reproductive system Flashcards
What does sexual reproduction involve?
Sexual reproduction involves formation of female and male gametes.
What do the gametes fuse to form?
A zygote and then the zygote develops into an embryo then the embryo develops into a fetus.
Give the role of the ovaries
To produce female eggs
Give the role of the fallopian tubes
Connects the ovaries to the uterus
Give the role of the uterus and cervix
Cervix is a ring of muscle that acts as a barrier for the uterus.
Give the role of the vagina
Elastic, muscular component that stretches the external genitalia or vulva to the cervix. The three main functions are:
- receiving sperm
- forms the birth canal
- allows loss of blood from the menstrual cycle
What is an example of positive feedback during pregnancy?
When oxytocin is released and stimulates contractions causing the cervix to dilate.
What does FSH stimulate the growth of?
Follicles within a ovary
What does a growing follicle start to produce?
Estrogen which inhibits the production of FSH which ensures that only one egg matures
Stimulates growth and repair of the lining of the uterus
What other hormone has a surge when the concentration of estrogen increases before day 14?
LH
After the egg is released, what happens to the follicle?
It becomes corpus leutum.
What does the corpus leutum release?
Progesterone
What does the concentration of progesterone inhibit?
Release of LH and FSH.
What hormone maintains the lining of the uterus?
Progesterone
What happens to the corpus luteum is fertilization does not occur?
It breaks down and the concentration of progesterone and estrogen decreases.
As the progesterone and estrogen falls around day 28, what happens?
The cycle begins again
What happens to the corpus luteum if fertilization occurs?
The placenta will take over the production of progesterone and this maintains the lining of the uterus during pregnancy.
What hormone begins the process if puberty and stimulates FSH and LH?
GnRH
What does the stimulation of FSH and LH lead to?
Onset of the menstruation.
What is endometriosis?
A condition where cells similar to the endometrium grow outside the uterus and this can be in the ovaries, or fallopian tubes, abdominal cavity, intestines, bladder and diaphragm can be affected.
What are the theories behind the cause of endometriosis?
Genetics
Malfunction of the immune system
Cells from the endometrium spread through the body via the bloodstream.
Give the physical symptoms of endometriosis
Pelvic pain
Pain during or after sex
Urination and defecating
Feeling sick
Constipation/diarrhoea
Infertility
Heavy periods
What can endometrial cells form outside of the uterus?
Lesions or adhesions that bleed each period leading to inflammation and scarring
How can common treatments relieve symptoms?
Pain killers to treat pelvic pain
Hormone-based treatment e.g. contraceptives, combined pill that reduces the production of hormones that regulate ovulation and menstruation.
Surgery to remove patches of endometrial tissue that can be done via laparoscopy and in some cases some or all of an organ affected by it may be removed e.g. appendix or a hysterectomy.
How are the eggs fertilised in IVF?
They are fertilised in a lab to form a zygote and the embryo produced is placed into the mother’s uterus.
Give stage 1 of IVF
Suppression of natural cycle
Stage 2 of IVF
Stimulating ovaries for more egg production
Stage 3 of IVF
Monitoring eggs
Stage 4 of IVF
Maturing eggs
Stage 5 of IVF
Egg collection
Stage 6 of IVF
Fertilising eggs
Stage 7 of IVF
Embryo transfer
Stage 8 of IVF
Pregnancy
What hormone is used to stimulate the ovaries?
FSH
Give the factors that affect the number of embryos transferred.
Mother’s age
IVF cycle
Quality of embryos.
