Female reporductive.pdf

Reproductive System Female NSCI5720 Vertebrate Anatomy and Physiology Female Reproductive System Functions Produces sex hormones Produces and develops reproductive cells Receives male reproductive cells Creates a site for fertilisation of ova Creates an environment for the ferti...

Reproductive System Female NSCI5720 Vertebrate Anatomy and Physiology Female Reproductive System Functions Produces sex hormones Produces and develops reproductive cells Receives male reproductive cells Creates a site for fertilisation of ova Creates an environment for the fertilised ovum to develop into an embryo Supports the embryo for the gestation period Parturition Mammary glands provide nutrition and immune protection Female Reproductive Organs  Ovaries Female gonads – equivalent to the male testes Located in the dorsal abdomen – caudal pole of the kidney Oval-shaped for most species Functions of the ovary Production of hormones Production of ova (gametes) Ova – multiple gametes Ovum – single gamete Production of Hormones  Production of Ova Oocytes (immature ova) are produced at or soon after birth, and remain in ovaries in an immature state (they are not constantly produced like in males) Oogenesis = process of development of ova in the follicles of ovaries. Oocytes become ova. Not all oocytes will progress to become ova - some will, some won’t  Ovarian Cycle Cyclical production of ova – development of an ovum from an oocyte. This occurs within a follicle, then at ovulation, the ovum is released from the follicle Follicle – ovum with surrounding follicular cells. Cells slowly change throughout the cycle and produce oestrogen hormones. Fluid begins to fill the follicle as it matures. Continuous cycle, triggered by the release of hormones from the pituitary gland (brain) Follicle stimulating hormone (FSH) – stimulates follicle development and oocyte maturation Luteinising hormone (LH) – initiates ovulation  Ovarian Cycle Development of ovum within follicle Release of mature ovum from follicle Development of corpus luteum (yellow body, produces progesterone) Degeneration of un-ripened follicles Degeneration of corpus luteum Ovarian Cycle The number of follicles that ripen, and therefore ova released varies with species -parous = bearing Uniparous – one offspring per pregnancy One ovum per cycle, one pregnancy Multiparous – multiple offspring per pregnancy, or have had more than one previous parturition Multiple ova per cycle Had babies before Nulliparous – not had any offspring  Uterine tubes (oviducts) The ovaries and the uterine horns are not connected – therefore, there needs to be a way of transmitting the ovum Uterine tubes = tubes that pass from the infundibulum (by the ovary) to the uterine horn But, the uterine tubes are not attached to the ovary – ova must be “caught” by the infundibulum This is a funnel with finger-like projections (fimbriae) at the end of the oviduct in contact with the ovary. Surrounds the ovary where the ova will be released from In humans, they are known as Fallopian tubes (not in animals)  Uterine tubes (oviducts) Function is to transport the ova released from the ovarian follicle to the uterine horn Lined with smooth muscle, which contracts to pass ova toward the uterine horn Fertilisation occurs in the uterine tube, if the female has been mated  Uterine Horns Commonly called “the womb” Sits between the bladder (ventrally) and the colon (dorsally) Two uterine horns converging to for the uterine body – proportions vary with species  Uterine Horns Uterine horns have three layers Endometrium Inner layer Simple columnar epithelium + glands Secretes mucus Myometrium Thick middle layer Made up of rings of smooth muscle Perimetrium Outermost layer Serous connective tissue layer (visceral peritoneum) Blends into the broad ligaments  Uterine Horns - Function Fertilised ovum/ova implants in the uterine horns, where it/they grows and develops Placenta forms a connection between the embryo and the uterine horn Provides O2 and nutrition to, removes CO2 and wastes from the foetus during gestation Gestation - pregnancy When fully developed, myometrium (smooth muscle layer in the uterine horn) contracts to expel the foetus Broad Ligaments Uterine horns are attached to abdominal wall by the broad ligament (connective tissue) Broad ligament – sheets of peritoneum (serous connective tissue) that contains blood vessels, and often contains fat Broad Ligament  Cervix Fibromuscular neck that separates the uterine body from the vagina Closed most of the time, apart from at oestrus and parturition Cervix opens to allow sperm to enter, and foetus to leave Cervices = pleural  Vagina Muscular tube between cervix and vulva Usually collapsed, and can expand Receives penis at the time of mating Birth canal during parturition Lined with glands that secrete mucus at time of breeding  Vestibule and Vulva Only parts of the female reproductive system that are external Vestibule Urethra opens on the floor/ventral part of the vestibule (urinary tract) Muscles contract during “the tie” Clitoris located in the vestibule – similar in composition to the male’s penis Vulva Not the vagina External genitalia