Female reproductive system Flashcards
What are PGC’s
Primordial germ cells
What are primordial germ cells responsible for
development of male and female germ cells
When is sex of embryo determined
chromosomally at fertilisation
What do primordial germ cells do at early stgae of embryological developement
Migrate from epiblast through primitive streak to the yolk sac
What is the structure of gonads in embryological development
genital ridge
What happens to PGC’s after move to yolk sac
Migrate into developing gonadal ridge through ameboid movement
What happens to the genital ridge
proliferates and penetrates the intermediate mesoderm to form primitive sex cords
What does the combination of the germ cells(genital ridge) and primitive sex cords make
indifferent gonad which development into either testes or ovaries can occur
What happens in female embryo when xx sex chromosomes present
As no Y chromosome no SRY gene
primitive sex cords degenerate and no testis cord
What happens because of no SRY gene
primitive sex cords degenerate and do not form testis cord
What happens to the epithelium of gonad in female embryo after sex cords degenerate
Continue to proliferate and produces cortical cords of which break into clusters surrounding each oogonium(germ cell) forming a primordial follicle
What are the 2 pairs of ducts ending at the cloaca in initial weeks of genital development
Mesonephric(Wolffian) ducts
Paramesonephric(Mullerian) ducts
What happens to female embryo ducts as no leydig cells to produce testosterone
Mesonephric (wolffian) duct degenerate
What other hormone/absence allows for development of paramesonephric(mullerian) ducts
Absence of anti- mullerian hormone
What part of paramesonephric duct forms uterine tubes
Cranial portions remain separated
What part of paramesonephric duct forms uterus and cervix
Middle portions fuse along the midline to form the uterovaginal canal
What part of paramesonephric duct forms Vagina
Caudal ends contact the urogenital sinus and sinus forms a sino vaginal bulb which proliferates for lower vagina.
upper vagina- fused paramesonephric ducts
Name the female organs of reproduction
2 ovaries, 2 uterine tubes(oviducts, uterus, cervix, vagina, vulva
Where does fertilization normally occur
Within uterine tube during passage of ovum from ovary to the uterus
Location of ovary
dorsal part of abdomen caudal to the kidneys in the lumar region
What is cortex(ovary)
Outer zone of ovary, composed of follicles in various stages of development, corpora lutea, and connective tissue stroma
What is medulla(ovary)
central area of the ovary, blood vessels, nerves, lymphatics, smooth muscle fibres and connective tissue fibres
What is the uterine tube
Duct running from ovary between layers of mesosalpinx to the tip of the uterine horn. Site of fertilization bringing sperm and oocytes together
Tube runs cranial direction to free edge of suspensory ligament then sharply turns caudal
What is the Infundibulum
expanded, funnel shapes ovarian end of uterine tube
the finger like projection on the free edge are called fimbriae
Role of finger like projections on free edge of infundibulum(fimbriae)
Pick up oocyte from surface of ovary and direct to infundibulum
What is the abdominal opening of the uterine tube
opening in the centre of the infundibulum, only opening of peritoneal cavity tot the outside of the female animal. dont exist in male
What is the uterus
expandable, tubular organ where embryo/foetus develops
What does the uterus consist of
A corpus(body)
A cevix(neck)
Two cornua(horns)
What is the shape of the uterus
Bicornuate- 2 long horns and a small body
Where is the fertilized ova implanted
equal distances along the horns allowing maximum amount of space for development
rare to be within uterine body
What is the uterine body
part of the uterus between the cervix and the uterine horns
What is the cervix
contricted caudal part of the uterus joining the uterus and vagina
it has a channel having opening both ends (internal and external uterine ostium) and is closed except for oestrus and birth
What is the uterine horns
2 musculo-membranous externsions of the uterine body located entireley within abdomen.
Name a adapation of uterine horns
In carnvious the uterine horns are very long horns compared to their body an adaptation for litter bearing
Adaptation litter bearing
Long uterine horns
3 uterine wall layers
Endometrium (Mucosal layer)
Myometrium (muscle layer)
Perimetrium (serosal layer)
Endometrium (mucosal layer)(detail)
lines lumen of the uterus and thickens depending on stage of the oestrus cycle
Myometrium (muscle layer)(detail)
underlying the endometrium is 2 layered muscular layer.
contain smooth muscles
And thicker internal circular layer of smooth muscle separated by a highly vascular stratum of connective tissue
Perimetrium (serosal layer)(detail)
Uterus is covered by serous membrane which continuous with the broad ligament
What is the vagina
Constitutes the cranial part of the female copulatory organ it extends from the external ostium of the uterus to the entrance of the urethra
Part of only the reproductive tract
Median position within pelvic cavity with rectum dorsally and bladder ventrally
What is the vestibule of the vagina
Caudal part of the copulatory organ
extends from the external urethral opening to the external vulva and combines reproductive and urinary function
What is vestibular bulbs
organized erectile venous plexuses in the vestibular walls of the bitch
bulbs erect in the copulatory tie and press against penis caudal to enlarged bulb of the glans
What is the vulva
formed by 2 labia that meet at dorsal and ventral commissures surrounding the vertical vulvar opening
Name the broad ligaments
Mesovarium
Mesosalpinx
Mesometrium
What is the mesovarium
cranial part of broad ligament
attaches ovary to the dorsolateral region of abdomindal wall
contains ovarian artery and vein
What is the mesosalpinx
lateral arising from mesovarium
contains uterine tube and holds it between its two layers
only part of broad ligament not attached to abdominal wall
what does mesovarium contain
ovarian artery and vein
what does mesosalpinx contain
uterine tube
What is the ovarian bursa
small peritoneal cavity enclosed by mesovairum and mesosalpinx
facilitates transports of ovulated oocytes into oviduct
dog encloses ovary completely
cat surronds ovary but wide communication to abdominal cavity
What is the mesometrium
Attach uterine horns and body to the dorsolateral body wall
round ligament of the uterus is in the free edge of the secondary fold of mesometrium
What is the suspensory ligament
Forms cranial boundary of the boundary of broad ligament
extends between ovary and last ribs near kidney
What is proper ligament of the ovary
caudal continuation of the mesovariums cranial free edge (suspensory ligament)
connects ovary to end of uterine horn
What is the round ligament
extends caudally toward inguinal canal and is from the lateral aspect of mesometrium
Where does ovarian artery go
branches of aorta and follows a convoluted course to the ovary and supplies ovary and detaches branches to uterine tube and tip of uterine horn
Where does uterine artery go
branch of vaginal artery and passes to uterus within broad ligament
branches supply body and horn of uterus
How many mammary glands for bitch
5 pairs
2 thoracic M1 M2
2 abdominal M3 M4
1 inguinal M5
How many mammary glands for queen
4 pairs
2 thoracic M1 M2
2 abdominal M3 M4
Do cortical cords form before or after degeneration of primitive sex
after
Does genital ridge epithelium proliferate to form primitive sex cords BEFORE OR AFTER PGC’s migrate to genital ridge
after
In embryonic development what absence of what hormone primarly leads to development of female reproductive tract
testosterone
What structure is derived from the urogenital sinus during female repro system development
vagina
What is primary structural adaptation in the uterus for litter-bearing in dog
long uterine horns
What connecting peritoneum structure supports the uterine tube
mesosalpinx
What is a main part of the avian female repro system (magnum)
magnum is responsible for albumen
What is the significance of the absence of the SRY gene in ovarian development
No Y chromosome so ensure primitive sex cords degenerate and no testis cord forms.
cortical cords develop surronding each oogonium with follicular epithelial cells to form primordial follicles->essential for development of functional ovary
What is the function of an ovary
Site of oogenesis and ovulation
endocrine gland-secretes hormones oestrogen and progesterone
What is the function of the uterine tube
collect and propel ova towards the uterine horn
usually site of fertilisation
What is function of the fimbriae on the infundibulum of the uterine tube
Catch ova as they are released and direct them into uterine tube
What is the function of the uterus
Location for implantation of embryo
Organ that provides space and nutrients required for growth of foestuses to full-term
What is endometrium
internal layer composed of glandular tissue and blood vessels and site of implantation
What is myometrium
layers of smooth muscle
What is mesometrium/broad ligament
Fold of visceral peritoneum that suspends uterus from dorsal body wall
free edge is thickened and forms round ligament
continuous with mesovarium and mesosalpinx
What changes occur in the endometrium during pregnancy and why
Endometrium thickens to provide nutrition and support the placenta
Why is the myometrium composed of smooth muscle
Allow expansion during pregnancy and reduction after
Produce strong contractions during parturition
What happens to the cervix during pregnancy
It becomes blocked by mucoid plug to prevent infections entering uterus
What does the mesometrium support
Supports uterine horns and body anchoring them to lateral body wall
ensure proper positoning of uterus in abdominal cavity
What does the mesosalpinx supports
Surrounds and supports oviducts/fallopian tubes
forms a portion of ovarian bursa which partially encloses the ovary
What is function of ovarian bursa
facilitates transports of ovulated oocytes into oviduct
What does the mesovarium support
connects the ovary to the dorsal abdominal wall
contains ovarian blood vessels, lymphatics, and nerves within the suspensory ligament of ovary
What roles do the broad ligaments play if facilitating the reproductive tract to perform its function
support, blood supply and lymphatic drainage, nerve innervation
How does broad ligament adapt during pregnancy and what is surgical considerations
Broad ligaments adapts through combination of mechanical stretching, vascular remodeling and hormonal influence
During a caesarean section of spay in a pregnant bitch the surgeon must account for the enlarged vascularized broad ligament.
