endocrinology - male and female reproductive system Flashcards
Main difference between male germ cells and females?
Males gametogensis begins at puberty and differtiate through out life as pool avaliable for subsequent spermatogenic cycles
Females before before have 1 ‘o’ oocytes within ovarian follicles halted in meiosis prophase
every month released
Steps of spermatogenesis (gametogenesis)?
Where exactly are sperm produced? (Which tubule)
Seminfierou tubules
histology of seminiferous? And function of each hormone?
As cells go to centre, mitosis + meosis until sperm in centre
tunica propia - outer layer
spernatgonium - germ cell
sertoli - help with hormones to make sperm
leydig cell - secrete hormones androgens
Specific function of sertoli cells
FSH receptors
Function: support develop germ cell with movement and nutrients from cap to cells
also hormone synthesis: activin/ inhbin (for FSH)
AMH stop develop uterus
androgen binding protien - help testosterone (binds to it) go to right place
specific function of Leydig cells?
LH receptors
hormone synthesis: on stimulation of LH produce
tesosterone (oestrogens)
Androstenedione DehydroEpiAndrosterone (DHEA)
(can be aromatised to oestrogens)
Female oogenesis stage and timings?
Oogonia develop into primary oocytes, forming primordial follices, during the 2nd trimester of pregnancy of mother
Menarche refers to the beginning of the menstrual cycle in women
Polar body degenerates and eventually does nothing
Folliclegenesis in ovaries? FOLLICULAR PHASE and then LUTEAL PHASE
Name each stage + describtion?
- Primordial follicle (1 ‘0’ Oocyte at birth)
from birth to puberty cells goes from primordial to primary
- Primary (=Preantral) follicle
1’0’ Oocyte and layers of granulosa (inside) cells and outer theca cells
- Secondary (=Antral) follicle
Fluid-filled cavity (antrum) develops
FSH and LH receptors
- Mature (=Graafian/Preovulatory) follicle DOMINANT ONE
Forms due to LH surge
2’ 0’ Oocyte formed
- Ruptures surface of ovary
6-7. Corpus Luteum
Progesterone & oestrogen (stim by LH)
In pregnancy, progesterone & oestrogen production taken over by placenta
Function of Theca Cells?
outer part of ovarian follicles
- support of folliculogenesis by structural and nurional support of growing follcile
- hormone syntheisis LH stimulate synthesis androgens ( testosterone)
Function of granulosa Cells?
inner
function: - hormone synthesis, FSH stimulate cells to convert androgens to oestrogens by aromatase.
secretes actin and inhbin (FSH)
after ovulation
turns into lutein cells. Produce progesterone (-ve feedback, promote preg by maint endometrium)
relaxin (helps endometirum prepare for preganancy and soften cervix)
What is the hypo thalamic - pit - gondal axis?
kesspeptin at top stimute GnRH releasing neurones
Effect of Prolactin on Axis?
ikiss peptin nhbited by prolactin, binds to prolactin receptors on kisspeptin neurones on hypo.
less tesosterone/ostrogen/progesterone ,etc.
lead to amenorrhoea AND osteoprosis as bones need oestrogen
Whhy does menstrual cycle has the cycle known?
At beg FSH and LH produced stimulate oestrogen but -ve feedback keeps in check
FSH kept in check/ slightly decreases so only follicle survives/stimulated + becomes dominant.
follicle release more ostrogen, changes to +ve feedback more FSH and LH highly increase causes allows follcile to develop (complete meiosis) and ovulation
LH then drops and leatal produce progesterone
compare ovarian cycle (of follicles) and uterine (of endometrial) cycle?
both driven by hormonal changes
Does temperature changes after ovulation?
Yes, increase due to progesterone
When is HCG produced?
Only produced by placenta, used in pregancy test
Which parts of male reproductive system produce seminal fluid?
Mainly acessory sex glands : seminal vesicless, prostate , bulbourethral glands
also small contribution from: epidymis/testis
What does semen contain?
speromotza, seminal fluid, leucotyes and poritentially virus
capictation of sperm where does it occur? (becoming able to fertilse
and what does it need?
in fallopian tube.
oestrogen and Ca2+ dependent
What happens in capacitation of sperm?
loss of glycoprotien coat
change in surface membrane characteristics
development of whiplash movement of tail
Describe stages of acrosome rxn
sperm binds to zp3, sperm receptor on zona pellicuda
Ca2+ influx into sperm (stimualted by progesterone)
causes for hyaluronidase and proteoyltic enz released from acrosome
allows sperm to penetrate zona pellicuda
Describe corical rxn and effects
fertilisation, entry of sperm into egg trigger cortical rxn,
cortical granules release contents degrade zona pellicuda due ZP2 and ZP3
prevent further sperm binding no receptors
and pronucleus join for diploid
What happens after fertilization?
moves down to uterus 3 days
recieves secretionsf rom uterine secretions
free living phase for 10 days before implantations
Stages of implantation?
attachment phase: outer trophoblast cells become in contact with surface epthileum
then
decidualisation phase: changes in underlying uterine stromal tissue
REQUIRES prog >>>>>> oesto
How do the lining and blastocyst interact to allow for adhesion?
ATTACHMENT PHASE
What factors are release that allow for ahesion and what do they do?
Leukaemia inhibtory factor - from endometrial cells stimulate adhesion of blastocyst to endometrial cells
IL11 - from endometrial cells is released intro uterine fluid
What happens in decidualisation phase?
AFTER AHDESION
Endometrial changes due to progesterone
Glandular epithelial secretion Glycogen accumulation in stromal cell cytoplasm
Growth of capillaries
Increased vascular permeability (→oedema)
Factors involved:
Interleukin-11 (IL11), histamine, certain prostaglandins & TGFb (TGFb promotes angiogenesis)
What hormonal changes happen after pregnancy?
Production of hCG produced by trophoblasts
hCG stimulate corpus luteum by LH receptors to ‘keeping making’ produce progesterone and oestrogen
inhibit LH and FSH (-ve feedback) as no need
without hCG corpus shrivel and prog/oest levels fall + cause endometrial wall to fall off + period
After 40 days
placenta takes over
How does placenta produce progesterone and oestrogen?
that placenta oesto and prog
from maternal and fetal DHEAs and pregenolone( for progesterone)
Changes in other maternal hormones during pregnancy?
Increase
ACTH, Adrenal steroids, Prolactin , IGF1 (stimulated by placental GH-variant) , Iodothyronines , PTH related peptides
Decrease: Gonadotrophins, Pituitary GH, TSH
Which endocrine hormones control partruiton? i.e labour
oxytocin act on myometrial and endometrial
aided by oestrogen and progesteron
uterine contraction, cervical dilation , milk ejection
which endocrine control lactation?
oxytocin - ejection
prolactin - prolactin
golacteria - due to prolactin not oxytocin
