Female reproduction Flashcards
Identify the major female reproductive organs
Ovaries, Fallopian tubes/oviducts, uterus, vagina, external genitalia, mammary glands
List the major functions of the female reproductive tract
secrete sex steroids that support female reproductive tract development and function produce other hormones (relaxin, inhibin) source of female gametes site of male semen deposition, fertilization site of embryo implantation, development expulsion of fetus at term nourishment of newborn
Which species have menstrual cycles and which have estrous cycles?
primates, humans- menstrual cycles all other species- estrous
Describe the functions of the ovaries both in terms of germ cell and hormone production.
produce gametes (secondary oocytes that develop into mature ova) produce progesterone, estrogen, inhibin and relaxin
Why is folliculogenesis in the horse unique?
reversed from normal Blood vessels in the periphery Oogenesis in central portion
Describe with diagrams the two-cell theory by which granulosa and thecal cells make estrogen
Describe what happens to a follicle following ovulation.
the secondary oocyte leaves the ovary and travels through the oviduct to the uterus; without the oocyte the follicle folds inward on itself, transforming into the corpus luteum, produces estrogen and progesterone
Describe the LH surge, what it does, and what controls it
as estrogen levels rise, it stops inhibiting LH/GnRH and actually becomes stimulatory; leads to LH surge; promotes formation of corpus luteum; triggers ovulation
List the major induced ovulators and describe induced ovulation
rabbit, felids, ferret, mink requires a stimulus to induce animal to ovulate (ex. cats-tactile)
Describe the role of relaxin in the female.
produced by corpus luteum, relaxes uterus by inhibiting contraction of myometrium, at end of pregnancy, increases flexibility of pubic symphysis and dilates uterine cervix
Describe the role of oxytocin in the female
causes myometrial contractions, results in expulsion of fetus, pitocin (oxytocin) used routinely in veterinary medicine for dystocia, short half-life
Name some clinical problems associated with female reproduction
Infertility Abortion (bacterial, viral, hormonal causes) Dystocia Cystic Endometrial Hyperplasia/Pyometra Vaginal Infections
Ovary
critical source of hormones and major target of hormones; site of folliculogenesis; paired glands homologous to testes
Oviduct
provide a route for sperm to reach ovum; transport secondary oocytes and fertilized ova from ovaries to uterus; infundibulum ends in fimbriae estrogen acts on it to stimulate oviductal development estrogen and progesterone regulate epithelial proliferation, epithelial secretory activity, ciliagenesis and ciliary beat in the oviduct
Uterus
opens into the cervix and the vagina; oviducts open into the uterus; 3 layers- perimetrium/myometrium/endometrium estrogen act on it to stimulate epithelial proliferation (inhibited by progesterone) progesterone stimulates glandular secretion both prepare uterus for implantation
Vagina
hormone target, part of female reproductive tract
Mammary glands
nipple has openings of lactiferous ducts modified sweat gland that produces milk function is regulated by oxytocin and prolactin; variety of hormones are necessary for its development
Menstrual cycle
seen in primates, humans
Estrous cycle
seen in species other than primates, humans
Wolffian duct
Develops into ovaries, oviduct, cranial 1/3 of vaginal
Primordial follicle
several formed each month, how many develop into primary follicles varies by species
Primary follicle
develop from primordial follicles; surrounded by granulosa cells, forms zona pellucida between granulosa cells and primary oocyte, stromal cells begin to organize into thecal layer
Secondary follicle
develop from primary follicles; theca differentiates into theca interna secreting estrogens and theca externa; granulosa cells secrete follicular fluid in antrum
Tertiary/ Graafian follicle
follicle just before being completely mature
Oocyte
mature follicle released during ovulation
Oogonia
during oogenesis, germ cells differentiate into oogonia and then proliferate extensively
Atresia
degeneration of most germ cells before birth
LH surge
occurs in induced ovulators after stimulus either during or after mating; causes giant surge in LH in the blood stream which stimulates ovulation
Corpus luteum (plural:corpora lutea)
developed during ovulation; if oocyte is fertilized it will persist, if oocyte not fertilized it is transitory
Progesterone
Secreted mainly by the corpus luteum, works with estrogens to prepare and maintain endometrium for implantation and mammary glands for milk production, inhibits many actions of estrogen, inhibits secretion of GnRH and LH
Estrogen
promote development and maintenance of female reproductive structures and secondary sec characteristics, increases protein anabolism including building strong bones, lowers blood cholesterol, inhibits adipose deposition, inhibit release of GnRH, LH and FSH
