Female Reproductive System Functions 1 Produce female sex

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Female Reproductive System Functions: 1. Produce female sex hormones 2. Provide fertile ovum via

Female Reproductive System Functions: 1. Produce female sex hormones 2. Provide fertile ovum via oogenesis 3. Receive sperm and provide site for fertilization 4. Provide environment for embryo to grow 5. Push offspring into world 6. Provide nutrition for newborn (lactation) Mosby items and derived items © 2008 by Mosby, Inc. , an affiliate of Elsevier Inc.

Female Reproductive Organs ► Ovaries ► ► ► Oviducts Uterus Cervix Vagina Vulva Ovary

Female Reproductive Organs ► Ovaries ► ► ► Oviducts Uterus Cervix Vagina Vulva Ovary Oviduct jcow Mosby items and derived items © 2008 by Mosby, Inc. , an affiliate of Elsevier Inc.

Female Reproductive Organs bitch Ovaries Oviducts Uterus Cervix Vagina Vulva

Female Reproductive Organs bitch Ovaries Oviducts Uterus Cervix Vagina Vulva

 Broad ligaments: sheets of peritoneum by which the ovaries, oviducts, and uterus are

Broad ligaments: sheets of peritoneum by which the ovaries, oviducts, and uterus are suspended. › › Mesovarium – supports ovary Mesosalpinx – supports oviduct Mesometrium – supports uterus Contain blood vessels, nerves, and fat Round ligament of uterus: Cord of fibrous tissue and smooth muscle in the broad ligament that extends from the uterine horn to the inguinal ring. › Cut during an OHE to allow removal of the uterine horn. Ligaments

 Suspensory ligament of ovary: Formed by the ovarian end of broad ligament attached

Suspensory ligament of ovary: Formed by the ovarian end of broad ligament attached to body wall in area of last rib During an OHE, it is “popped” to allow visualization and removal of the ovary.

Ovaries Female gonads In dorsal abdomen near kidneys Species variation in appearance Functions ›

Ovaries Female gonads In dorsal abdomen near kidneys Species variation in appearance Functions › Site of oogenesis (however, the animal was born with a predetermined number of oocytes) › Production of estrogens and progestins

Hormones Source Hormone (that control estrous cycle) Effect Ant Pituitary Ovary Granulosa cells Corpus

Hormones Source Hormone (that control estrous cycle) Effect Ant Pituitary Ovary Granulosa cells Corpus Luteum LH -causes Granulosa cells to develop -causes production of estrogen -surge causes ovulation FSH -stimulates egg production Estrogen -makes female receptive to male -causes proliferation of uterine tissue -produces female characteristics Progesterone -prepares uterus for zygote (fert egg) -maintains pregnancy Mosby items and derived items © 2008 by Mosby, Inc. , an affiliate of Elsevier Inc.

 Each cycles consists of the development of ovum, ovulation, formation of corpus luteum,

Each cycles consists of the development of ovum, ovulation, formation of corpus luteum, and degeneration of unripened follicles and corpus luteum Influenced by follicle stimulating hormone (FSH) and luteinizing hormone (LH) Number of follicles produced is dependent on the species › Uniparous species: normally give birth to one offspring at a time › Multiparous species: give birth to litters due to multiple ova production per cycle Ovarian Cycle

� Primary/primordial follicle: immature oocyte surrounded by a single layer of follicular cells Ovarian

� Primary/primordial follicle: immature oocyte surrounded by a single layer of follicular cells Ovarian Cycle › Stage that immature oocytes reside in until they become activated to mature �Activated by FSH to begin developing (follicular recruitment/activation) �Once activated, they are called growing follicles. � Growing follicle: cells of the follicle become thickened and start to multiply in layers around the developing oocyte. › These thickened cells are called granulosa cells. �produce estrogen to prepare for breeding and pregnancy �follicle grows rapidly in size Follicular cells

� Granulosa cells produce increasing amounts of estrogens as follicle becomes larger � Fluid-filled

� Granulosa cells produce increasing amounts of estrogens as follicle becomes larger � Fluid-filled spaces form between granulosa cells › Spaces gradually merge into one large fluid-filled space: the antrum � Mature follicle (graafian follicle): follicle has reached maximum size › Oocyte sits on top of granulosa cell mound (cumulus oophorus), surrounded by thin layer of granulosa cells (corona radiata) › production of estrogen peaks, along with LH production, causing ovulation to occur Ovarian Cycle

� Rupture of mature follicle and release of ovum (egg) into oviduct as a

� Rupture of mature follicle and release of ovum (egg) into oviduct as a result of the rising LH levels › Surface of mature follicle weakens and ruptures › Fluid from antrum is released, carrying the ovum with it � Empty follicle fills with blood (corpus hemorrhagicum). � Induced ovulators: ovulation only occursafter breeding › Cat, rabbit, and ferret Ovulation

� High levels of LH stiumulates the formation of the CL › Formed by

� High levels of LH stiumulates the formation of the CL › Formed by divisions of granulosa cells that line the corpus hemorrhagicum. � Produces progestins (primarily progesterone) › Necessary for maintenance of pregnancy If ovum implants in uterus, an endocrine signal is sent from placenta to ovary and the corpus luteum is maintained. � If ovum is not fertilized, the corpus luteum will degenerate. � Any follicle that doesn’t develop undergoes atresia. � Corpus Luteum

a. k. a. fallopian tubes � Extend from tips of uterine horns � Infundibulum:

a. k. a. fallopian tubes � Extend from tips of uterine horns � Infundibulum: enlarged opening at ovarian end of each oviduct � Oviducts › not attached to oviduct � Fimbriae: muscular projections form margin of infundibulum; help properly position infundibulum Smooth muscle fibers in walls � Muscle contractions and cilia lining guide ovum toward uterus � Usual site of fertilization �

Uterus hollow, muscular womb where fertilized ovum implants forms part of placenta that keeps

Uterus hollow, muscular womb where fertilized ovum implants forms part of placenta that keeps fetus alive grows during pregnancy Usually Y shaped › Uterine body forms base of Y › Two uterine horns form arms Cat Horse Cow Human

Uterine wall layers: � Endometrium: › Inner layer composed of simple columnar epithelium and

Uterine wall layers: � Endometrium: › Inner layer composed of simple columnar epithelium and glands that secrete mucus and other substances � Myometrium: › Thickest layer, made of smooth muscle � Perimetrium: › Outermost layer, covered by visceral peritoneum Uterus

 Smooth muscle sphincter between body of uterus and vagina › Controls access to

Smooth muscle sphincter between body of uterus and vagina › Controls access to lumen of uterus from vagina Normally tightly closed, except during estrus and parturition › opens to admit sperm during breeding › at birth, fetus is pushed against cervix until it dilates or opens. Cervix Mare Cow Sow Bitch

Vagina: Muscular tube extends caudally from cervix and connects it with vulva � receives

Vagina: Muscular tube extends caudally from cervix and connects it with vulva � receives penis at breeding � birth canal during parturition � stretchable and is lined with mucous glands. � Vulva: � Only portion of female repro tract that is visible from the outside › Labia (lips) - external boundary › Clitorus – equivalent to penis � erectile tissue and a sensitive glans › Vestibule – entrance to vagina, location of urethral opening Vagina and Vulva Urethral opening

Estrous Cycle � Spermatozoa are constantly produced so testosterone is fairly constant in male

Estrous Cycle � Spermatozoa are constantly produced so testosterone is fairly constant in male and he is always ready for breeding. � In domestic animals, breeding takes place only when chances for pregnancy are the greatest. › This is known as estrus or heat › timing of breeding is controlled by the estrous cycle of the female � Estrous cycle is beginning of one heat period to beginning of the next. › Controlled by FSH and LH › Different species have different estrous cycle patterns.

Estrous Cycle Intervals � Polyestrous: animals that cycle continuously throughout the year if they

Estrous Cycle Intervals � Polyestrous: animals that cycle continuously throughout the year if they are not pregnant › cattle and swine � Seasonally polyestrous: animals with seasonal variations in estrous cycles › horse, sheep, cat � Diestrous: animals with two cycles per year, usually spring and fall › dog � Monoestrous: animals with one cycle per year › fox and mink

Estrous Cycle Estrous cycle stages: › Proestrus › Estrus › Metestrus › Diestrus ›

Estrous Cycle Estrous cycle stages: › Proestrus › Estrus › Metestrus › Diestrus › Anestrus (in some species)

Proestrus Follicles begin developing and growing � Output of estrogen increases accordingly � Linings

Proestrus Follicles begin developing and growing � Output of estrogen increases accordingly � Linings of the oviduct, uterus, and vagina thicken to protect against breeding trauma › Vaginal smear can be done to determine heat � Estrus � � � Heat Period of sexual receptivity in the female; signals male that female is ready Estrogen level production peaks Ovulation occurs near end of estrus in some species Induced ovulator species remain in a prolonged state of estrus if not bred › cat, rabbit

Metestrus Period after ovulation during which corpus luteum (CL) develops � Progesterone produced by

Metestrus Period after ovulation during which corpus luteum (CL) develops � Progesterone produced by corpus luteum temporarily inhibits other follicles to develop in ovary � Lining of uterus prepared for implantation of a fertilized ovum � Diestrus Corpus luteum at maximum size and exerting maximum effect � If fertilized ovum implants, CL is retained well into pregnancy � If no pregnancy occurs, CL degenerates at end of diestrus › Animal then either goes back into proestrus or ovary shuts down and animal goes into anestrus � Anestrus Temporary ovarian inactivity � Seen in seasonally polyestrous, diestrous, and monoestrous animals �

False Pregnancy • • • Also called pseudocyesis or pseudopregnancy Affected animals may act

False Pregnancy • • • Also called pseudocyesis or pseudopregnancy Affected animals may act or look pregnant Is an exaggerated diestrous period Usually resolves spontaneously or through the use of hormones. Signs: builds nest, hoards/mothers toys, mammary glands enlarge/produce milk, pyometra Mosby items and derived items © 2008 by Mosby, Inc. , an affiliate of Elsevier Inc.

Meiosis Stem cell has same chromosomes as other somatic cells (2 n) � Which

Meiosis Stem cell has same chromosomes as other somatic cells (2 n) � Which chromosomes go to which daughter cell is entirely Chromosomes from mother random 2 n=4 � Chromosomes from father http: //www. stolaf. edu/peo ple/giannini/flashanimat/c elldivision/meiosis. swf and become attached http: //highered. mcgrawhill. com/sites/0072495855/student_view 0/chapter 2/animation__comparison_of_ meiosis_and_mitosis__quiz_1_. html http: //highered. mcgrawhill. com/sites/0072495855/stu dent_view 0/chapter 28/animati on__stages_of_meiosis. html n=2 http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/ch apter 50/animations. html#