S2 The female reproductive system and Development of the reproductive tracts Flashcards
what is the ovary
ovum producing reproductive organ
what is the arterial supply of the ovary
comes from ovarian arteries which are direct branches off the abdominal aorta
what is the venous drainage of the ovary
comes from the pampiniform plexus that converges to form the right ovarian vein which enters the IVC and the left ovarian vein which enters the left renal vein. Ovary lymphatics drain to the para-aortic nodes
what are ovarian cysts ?
fluid filled lesions which can be benign or malignant, patient shall present with pain or bloated
is the ovary covered fully by peritoneum ?
no, the ovary is suspended but not covered fully by peritoneum allowing its oocytes to be released into the peritoneal cavity that can subsequently be trapped by the fimbriae of the uterine tubes
what is the uterus ?
thick walled organ where the embryo can implant and develop
anterior to uterus is the bladder, posterior is rectum
what happens to the uterus during pregnancy ?
pushes organs such as the stomach and intestines so women can get acid reflux or constipation. pushing on bladder can increase urinary frequency
where is the site of fertilisation ?
uterine tubes are the site of fertilisation, in the ampulla. During ovulation, the egg ruptures through the wall of the ovary and enters the peritoneal cavity
what is the cervix made up of
the internal os, which opens onto the uterine cavity
endocervical canal
the external os, which opens into the vagina
before pregnancy, the external os of the cervix is round shaped after it is slit-shaped
what are peritoneal ligaments of the uterus ?
broad ligament - peritoneal fold
round ligament and ligament of the ovary - remnants of the gubernaculum- pulls the gonads down to the pelvis
suspensory ligament of the ovary - neurovascular pathway bulging into the peritoneum
what is the broad ligament ?
double layer of peritoneum that extends from the side of the uterus to walls and floor of the pelvis
contains :
the suspensory ligament surrounds the ovarian vessels
the mesovarium suspends ovary
the mesosalpinx attaches the ovary to fallopian tube
the mesometrium is the mesentery for the uterus itself
what is the ligament of the ovary
remnant of the gubernaculum, attaching the ovary to uterus
what is the round ligament
also a remnant of the gubernaculum and attaches the ovary to the labium majus
what is the blood supply of the uterus
derived from uterine artery (from the internal iliac artery) with some anastomosing with the ovarian artery
venous drainage is via uterine veins
the ureters run under the uterine artery “water under the bridge’. In males, ureters pass under Vas Deferens
describe the angles of the uterus
the uterus is anterverted(tipped anterosuperiorly relative to the axis of the vagina) and anteflexed ( flexed anteriorly relative to the cervix, creating the angle of flexion). Angles must be <180, thus when the bladder is empty, the uterus lies in the transverse plane. this position is maintained by the broad ligament
describe the microanatomy of the vagina
stratified squamous epithelium lines the vagina. it contains glycogen as they are the food of lactobacilli - the bacteria in the uterus, which turn it into lactic acid, creating the low pH
during early embryonic development what 3 germ layers arise ?
ectoderm, mesoderm and endoderm
the intermediate mesoderm is where the kidneys, gonads and genitalia develop
when does the embryo fold and how does this relate to development of the reproductive tracts ?
in the 4th of development creating a cavity inside the embryo with a gut tube suspended within it
as the embryo folds , it pinches off the yolk sac forming a gut tube, the hindgut is the region where repro and urinary tract development occurs
which tracts share a common caudal opening
GI, REPRO and URINARY
describe the nature of the hindgut
the hindgut ends in a dilated structure - the cloaca which is closed to the outside by the cloacal membrane so there is no mesoderm. Mesoderm gives rise to the CVS system and therefore blood vessels so as this membrane is avascular it shall die and rupture giving us an opening
where is the gonad derived from
intermediate mesoderm and Primordial germ cells , when PGC migrates to the gonad, they direct the development of the repro tract . they undergo gametogenesis giving sperm or oocytes
mesonephric duct contributes to the differentiation of the internal genitalia
what are primordial germ cells
arise in the wall of the yolk sac - migrate into the retroperitoneum, along the dorsal mesentery
how does the gonad develop
PGC migrate to the gonadal ridge where they shall eventually give us gametes
the ridge has mesothelial cells, which gives structures that help develop PGC (males - seminiferous tubules, females - ovarian follicles)
mesenchymal cells in the ridge shall produce supprting cells (males - sertoli cells, females - ovarian support stroma)
y chromosome in men has sex determining region - SRY, producing the gamete testis, absent in females so produces ovaries
what are the hormones produced by the internal genitalia during development ?
testis produce androgen class hormones which influence the development of the internal genitalia androgens maintain the mesonehpric duct - mesonephric/wolffian will give us the epididymis, vas deferens and seminal vesicle the ovary doesnt produce many androgens paramesonephric duct shall dominate as a result paramesonephric/mullerian will give us the uterus, cervix and 1/3 vagina
