A collection suite of final obstetrics and gynaecology MD notes to ace your penultimate and final year exams!
Look no further and save the stress of accessing multiple resources as this PDF collates and summarises information from several resources including but not limited to:
-Talley and O�...
REPRODUCTIVE SYSTEM
REPRODUCTIVE EMBRYOLOGY
Female Male
• Indifferent Gonads are derived from BOTH germ cells & primitive sex cords:
o Genital/Gonadal ridge [mesothelial layer of the peritoneum derived from germ
cells of endoderm in Week 4]
Indifferent o primitive sex cords [proliferation of epithelium of the genital ridges]
stage
*NB: Genital ridge (i.e. gonads) connected to scrotum/labia via gubernaculum ( a ligamentous
[Wk 6-7] structure derived from mesenchyme)
• No Y chr. = No SRY gene Mesenchymal cells migrate to • SRY gene = triggers primitive SAME
cloacal membrane è forms cloacal sex cord development to form Ø Proliferation of ectoderm and
• No Leydig cells = No testosterone è
folds: testis cords surrounded by
primitive sex cords degenerate = NO mesoderm around closed
• Fusion of folds cranially = tunica albuginea membrane forms genital
testic cords formed
genital tubercle • Testis cords = 2 cell types = tubercle, genital swelling and
• No Sertoli cells = NO anti-mullerian congenital fold
• Fusion of folds caudally = Sertoli cells & Leydig cells
hormone ® paramesnopheric ducts
urethral folds (anterior) and
Un- • Gonadal epithelium proliferate è
anal folds (posterior)
differentiated becomes cortical cords ® surround
stage germ cells with epithelial follicular • Either side of folds = Genital
cells ® primordial follicle swellings
1. Sertoli cells (germ) ® epithelial Testes secrete androgen (DHT) to:
Anti-mullerian hormone cells ® Secrete anti-Mullerian
Oestrogen causes: hormone to degenerate • Elongate genital tubercle è
• paramesnopheric ducts = fallopian Paramesonephric ducts phallus
tubes & uterus, cervix and upper 1/3 of • Genital tubercle elongates
(becomes appendix testis) ®
vagina è clitoris
At puberty: cords acquire • Pull Urethral folds è
• Proximal part = separature tube • Urethral folds (labia minora) lumen ® become seminiferous urethral groove è fold over
& genital swellings (labia è penile urethra [4TH
• Distal part – uterus fusion 2. Leydig cells ® mesoderm cells MONTH]
majora) do NOT fuse
® produce TT to induce
• Urogenital groove remains mesonephric ducts • Genital swellings è scrotal
NB: urogenital sinus è sinovaginal bulbs è open è vestibule differentiation è epididymis, swellings, moving caudally
lower 2/3 vagina vas deferens and seminal to eventually form the
vesicles scrotum
• Ovaries migrate caudally but to lesser extent than testes è reaches just within • Testes migrate caudally as foetus grows
the true pelvis
• 28th week: Testes enter inguinal canal è reach scrotum by 33rd week
• Remnant of gubernaculum = ovarian ligament + round ligament of the uterus [retains testicular arterial supply from lumbar aorta]
• Remnant of gubernaculum = Scrotal ligament
ANOMALIES
• Hypospadius = external urethral orifice on ventral surface of
penis/glans
• Cryptorchidism = failure of testes to descend into scrotum leading to
ectopic testes [due to unusual descent route]
Descent of
gonads • Ectopic testes – undescended testes away from normal descent
pattern
, NORMAL MENSTRUAL CYCLE (21-35 days)
MENSES PHASE
Follicular phase varies Luteal phase is FIXED = 14 days Loss of star-
shaped glands
Stromal (slough +
haemorrhage)
PROLIF PHASE
Test tube glands
Anti-Mullerian hormone = indicates SIZE of
Mitotic figures
primordial follicle pool = GF secreted by
primordial follicles
SECRET PHASE
Star shaped
corkscrew gland
dilated
Coiled arteries
Stages Day / Length Hormones Event
0-13 (Variable) • 1st day of cycle = 1st day of period
(Older = shorter - fewer • Folliculogenesis = primordial follicles develop into a single mature, dominant Graafian follicle
Phase 1: follicular eggs, ↑FSH
[*limited # of follicles at birth]
(proliferative) PCOS = longer as no
Primordial ® primary ® secondary ® tertiary “antral” follicles ® Graafian follicles
dominant follicle to
suppress others) ↑Estrogen • Estrogen causes endometrial proliferation = thicker endometrium
HPA +ve feedback • ↑ 17β-oestradiol ↑↑ FSH & ↑↑ LH è ovulation
Phase 2: • Breakdown wall of graafian follicle ® ruptures ® releases secondary oocyte into peritoneal
14
mid-cycle or cavity
[LH surge day 9-16] ↑↑ FSH & LH
ovulation
• Picked up by fimbriae of Fallopian tube ® infundibulum ® ampulla via ciliary movement of tubal
epithelium on fallopian tube
1) ↑↑ LH → (+) theca cells → ↑ progesterone (major) drive development of corpus luteum
Day 15-28 2) Corpus luteum (ruptured Graafian follicle (i.e. granulosa and theca cells) è also
Phase 3:
Fixed at 14 days ↑ LH = synthesizes/secretes17β-oestradiol
luteal (secretory)
[ovulation to start of ↑ progesterone
phase • makes endometrium more glandular support embryo implantation
menstruation]
• increases hypothalamic-set point to raise basal body temperature
• Corpus luteum regresses ® replaced by fibrotic scar (corpus albicans)
o Spiral arteries contract to reduce blood loss during menstruation
Menses
o regression = abrupt loss of progesterone and 17β- oestradiol
• No fertilisation = endometrial lining sloughs è menstrual bleeding
Phase 4: menses of ovulation day + 14 days • Fertilisation è syncytiotrophoblasts secrete hCG è preserves corpus luteum
pregnancy = menstruation o Synctiotrophoblasts produce villi to increase surface area around maternal
uterine blood vessels
Pregnancy o Thin membrane of cytotrophoblasts allows diffusion and removal of nutrients,
wastes, gas ® gradually develops into placenta
• corpus luteum continues to produce/secrete progesterone and 17β-eostradiol
• After 8 weeks: Placenta takes over to produce PG, E2
Hormone Oestrogen Progesterone
Cells Granulosa cells Theca cells
Origin Ovaries Corpus luteum (Ovary) /
Placenta (5-10/40)
Role Develop Female 2o sex Maintain pregnancy
characteristics (breast, Ø Drive corpus luteum
vulva, vagina) development
Fallopian • Proliferation • Reduce # of cilia
tube • Secretion of sugar • Reduce secretions
rich fluid
Endometrial • Angiogenesis in Thicken and maintain
effect uterus endometrium
• Endometrial
proliferation
Cervix Thins cervical mucus Thicken cervical mucus Hormonal Changes During Puberty (TANNER STAGING)
1) GH increases initially è GROWTH spurt
Other Stop milk production • Stop milk production
• ↑ basal body temp 2) HT secretes GnRH during sleep then during day ® rising FSH/LH ® rising
(peripheral vasodilation + estrogen and progresterone levels
increased metabolism) 3) FSH levels plateau (year before menarche)
• ↑ tidal volume (relax
diaphragm and intercostals) 4) LH continue to rise and spike just before they induce menarche
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller firstclass64. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £6.40. You're not tied to anything after your purchase.
