Female Reproductive System Flashcards
What is the difference between lifespan in women and men?
Lifespan in women is shorter than men.
Why do males’ gametes suffer from less mutations?
Because males’ lifespan is longer than females’.
Why is males’ lifespan longer than women’s’?
Because oogenesis stops at prophase 1 when the woman was developing inside her mother.
Mother was carrying the daughter and the eggs that can produce her grandchild too.
When does cell division in spermagonial stem cells start?
When the boy begins puberty.
For how long is cell division in spermagonial stem cells last in men?
It will continue through most of his life.
What is the disadvantage of long lifespan in men of cell division?
As these cells renew they are more likely to pick up de novo mutations –> affect his offspring.
How many new mutations will the man have in his spermatogonial cells by age 40?
3-4 times as many new mutations.
With what might higher paternal age be associated?
With an increased risk of premature birth.
And low birth weight.
How much should significant values be to indicate an increased risk of premature birth and low birth weight?
Above 1.
How much should confidence intervals be of error bars, based on distribution of birth within each paternal age group?
99% confidence intervals.
When does the % of live birth from ART peak?
In late 20s.
When is the success rate of live births from ART very poor?
By mid-40s.
When does LH of getting pregnant drop?
When age increases.
With what does infertility rate increases?
With age.
Which factors hold the ovary in place in female anatomy?
Supporting ligaments.
From where does uterine tubule/fallopian tube run?
From ovary to uterus.
Where does uterus open?
To vagina via cervix.
What does the open nature of the female tract mean?
The cervix produces mucus to protect sterile tract.
What does the left hand side of female anatomy show?
The intact view.
What does the right hand side of female anatomy show?
A cut through of the tract.
Of which factors does ovary consist?
Of follicles at various maturation stages.
Why is the end not directly ovulated into the tubule?
Because the ends of the tubule/fimbriae/fingers help to grab the egg –> take it into the tubule.
What does the tubule do?
It helps move the egg down the tubule.
How does the tubule help to move the egg down the tubule?
It has ciliated cells that beat in harmony.
What is the Ampulla region of the tubule thought to be?
The site of fertilisation.
Where does the egg/developing embryo move, regardless of fertilisation?
Down to the uterus.
What happens to the embryo if fertilisation occurs?
It implants into the endometrium.
What occurs beneath the endometrium?
The myometrium.
What is the myometrium?
A muscular lay = place.
What is the perimetrim?
The outer most layer.
What happens to the endometrium and egg if fertilisation hasn’t occurred?
They will be lost upon menstruation.
What happens during the female lifespan?
Primordial germ cells –> divide –> begin to –> dye off.
What the germ cells division and dye off is part of?
The developmental natural selection as female baby develops.
How many primordial follicles occur at birth?
1M.
How many of the 1M primordial follicles will be recruited to develop each month?
Only some.
How many of 1M primordial follicles will be ovulated as the others die?
Only 1.
What happens in Turners syndrome?
Partial/complete absence of X chromosome.
How many people suffer from Turners syndrome?
70-80%.
What happens to the people that suffer from Turners syndrome?
They have no spontaneous pubertal development.
How many people with Turners syndrome experience primary amenorrhea?
90%.
What is ‘primary amenorrhea’?
Failure of menstrual cycle.
What happens to the 10% of people with Turners syndrome if they do not experience primary aemenorrhea?
They possess a small residual of ovarian follicles at birth or early childhood.
With what is smoking associated?
With increased risk of infertility.
Why do virus and infections cause infertility?
Because of the inflammatory response which damages tubules and ovaries.
What do Autoimmune conditions cause?
Follicle death.
What do Chemotherapy and Radiotherapy prevent?
Cell division.
What is the consequence of chemotherapy and radiotherapy preventing cell division?
Damage of follicles.
How is a secondary follicle with its fluid in an ovary called?
Antrum.
By what is the oocyte surrounded?
By the zona pellucida.
What is the zona pellucida?
A protective glycoprotein layer.
What are the cumulus cells?
Specialised epithelial cells.
With what are the cumulus cells ovulated?
With oocyte.
Why are the cumulus cells ovulated along with the oocyte?
To form the cumulus oocyte complex.
Why are Granulosa cells and theca cells important?
For hormone production.
What does a woman, elephant shrew, some bats and chimpanzees have in common?
They all menstruate.
Into how many phases does menstrual cycle divided?
Three phases under hormonal control.
What happens when the end of one cycle/menstruation happens?
A new one starts.
By what is a new cycle driven?
By events in the hypothalamus.
What do the events in the hypothalamus release?
GnRH.
What is GnRH?
A peptide hormone.
Where does GnRH act?
Locally on anterior pituitary.
What does GnRH cause?
Release of two peptide gonadotropin hormones = FSH + LH.
What happens to some follicles during the initial follicular and proliferative phase?
They are sensitive to FSH –> begin to mature.
What does the secondary follicle begin to secrete as it is formed the thecal cells?
Oestrogen.
How many roles does Oestrogen have?
2.
What are the roles of Oestrogen?
- Stimulating endometrial growth.
2. Increasing LH release from anterior pituitary via positive feedback.
What happens in mid-cycle?
Elevated oestrogen production causes LH surge = swell.
What does LH surge trigger?
Ovulation.
What do the remnants = υπολείματα, of the mature follicle become?
A structure called ‘corpus luteum’.
What does ‘corpus luteum’ produce?
Progesterone + oestrogen.
Why does corpus luteum produce progesterone and oestrogen?
To maintain the endometrium in preparation for embryo implantation.
How is the maintaining of the endometrium in preparation for embryo implantation called?
The ‘secretory phase’.
What do the high levels of hormones suppress?
The release of GnRH/FSH + LH.
Why do the high levels of hormones suppress the release of GnRH/FSH + LH?
to prevent the next round of maturation from starting too soon.
What happens to corpus luteum if implantation does not occur?
It will naturally die.
What does the drop in oestrogen and progesterone production cause?
The endometrium o begin to die and start menstrual phase.
What does the death of endometrium and start of menstrual cycle relieve?
The negative feedback on the hypothalamus and pituitary.
What happens to the hypothalamus and pituitary when their negative feedback is relieved?
They release their hormones again.
They begin the next round of oocyte maturation.
Of what does the Primordial follicle consist?
Of oocyte enclosed by single layer of flattened epithelial cells/granulosa cells.
What does the induction by hormones/growth factors cause?
Morphology change.
What happens in morphology change when hormones/growth factors are induced?
Granulosa cells become cuboidal.
Follicles become primary.
When are secondary follicles formed
When granulosa cells proliferate and become layered.
Which cells surround the follicle, in humans?
Thecal cells.
In what function do granulosa cells and thecal cells participate?
In sex steroid synthesis.
Where does de novo progesterone synthesis in thecal cells result?
In testosterone production.
Where does testosterone production diffuse?
Into granulosa cells.
To what is testosterone production converted when it diffuses into granulosa cells?
To oestrogen.
What does post ovulation, LH/FSH surge upreluate?
Enzymes in granulosa cells –> increase –> progesterone production.
What do granulosa cells produce when they increase progesterone production?
Oestrogen and progesterone.
When does a tertiary follicle form?
When the fluid filled cavity/antrum is complete.
What do thecal cells produce?
An androgen progenitor.
Why do thecal cells produce an androgen precursor?
In response to LH.
Where does the androgen precursor from the thecal cells diffuse?
Into the adjacent granulosa cells.
What do the adjacent granulosa cells do to the androgen precursor once it diffuses in them?
They enzymatically alter it –> produce –> oestradiol.
For what molecule is cholesterol a precursor?
For androstendone.
Where is androstendone aromatise?
In the granulosa cells.
Why is androstendone aromatised in the granulosa cells?
To produce oestradiol.
What do thecal cells produce?
Progesterone.
From which molecule do thecal cells produce progesterone?
From the intermediate pregnenolone.
When do thecal cells produce progesterone from pregnenolone?
After ovulation in conjunction with remaining granulosa cells.
What do the remaining granulosa cells form together?
The corpus luteum.
What do the ovulated granulosa cells/cumulus cells surrounding the oocyte continue to produce?
Oestradiol + progesterone.
Under which influence do the ovulated granulosa cells continue to produce oestradiol and progesterone?
FSH.
What happens to the sperm after it has fused to the plasma membrane of the oocyte?
It fuses the DNA decondenses as it begins to form the male pro-nucleus.
What does the oocyte enter after ovulation?
The tubule.
By what can the tubule be fertilised?
By a spermatozoon.
Of what does the zygote consist?
Of the male and female pro-nuclei.
What the zygote become after the oocyte completes meiosis?
A diploid single cell embryo.
Where does the zygote progress after oocyte completes meiosis?
Down the tubule.
What does the zygote undergo, down the tubule, after the oocyte completes meiosis?
Cell division as it moves.
How many main cell types do the cells form by day 5?
2.
Which are the 2 main cell types the cells form by day 5?
- Trophoectoderm.
2. ICM.
Where does the Trophoectoderm contribute?
To formation of the placenta.
What does ICM become?
The baby.
What is trophoectoderm by day 8-9?
A blastocyst.
Into what is ICM divided by day 8-9?
Into the 2 layers:
- Hypoblast.
- Epiblast.
To what does hypoblast contribute?
Chorion.
Amniotic sac formation.
What is ‘chorion’?
Outer most membrane surrounding the embryo.
Example = The amniotic sac.
What is the ‘epiblast’?
The pluripotent primary lineage.
What will the ‘epiblast’ form in a complex process of differentiation called ‘gastrulation’?
The definitive germ layers.
Into where does the blastocyst implant?
The uterine epithelial cell lining.
Where does trophoectoderm open?
Out of the zona pellucida.
How many cell types does trophoectoderm contain?
2.
What does the epiblast form?
The fetus.
Into how many germ layers does epiblast differentiate?
3.
Which are the three germ layers epiblast differentiates into?
- Ectoderm.
- Mesoderm.
- Endoderm.
What do cell from each layer do?
They differentiate.
What do cells from each layer become after they differentiate?
Fully differentiated cell types in specific areas of the body.
What do women have?
A well defined fertility window.
In which context must the menstrual cycle be discussed?
Of ovarian and uterine changes.
What does the stage of the cycle affect?
Sperm capacity.
Why does the stage of the cycle affect sperm capacity?
To progress up the tract.
By what is the menstrual cycle and oocyte development driven?
Cyclical hormonal changes in the CNS and ovary.
What does follicle maturation produce?
A mature egg of well defined structures.
What does early developmental stages involve?
Repeated cell division.
Continued regional specialisation to produce all cell types.
