ADSC 2010 Lecture 25Outline of Last Lecture I. EpididymisII. Vas Deferens or Ductus DeferensIII. UrethraIV. Accessory Sex GlandsA. Seminal VesicleB. Prostate GlandC. Bulbourethral or Cowper’s glandV. Penis**FEMALE ANATOMY**VI. OvaryVII. Oviduct or Fallopian TubeOutline of Current Lecture I. UterusA. Uterine HornsB. Uterine BodyC. CervixII. VaginaA. CapacitationIII. VulvaIV. ClitorisV. Reproduction- Ovarian CycleA. Follicles1. Primary2. Secondary3. Tertiary4. GratianB. OvulationC. Corpus LuteumD. Fertile Life of Ova and Sperm1. Ova2. SpermE. FertilizationVI. Reproduction- Embryonic DevelopmentA. Blastocyst1. Inner cell massa. Endodermb. Mesodermc. Ectoderm2. Trophoblast3. Blastocyst CavityVII. Reproduction- ImplantationA. ImplantationB. Implantation TimesVIII. Reproduction- Placenta A. Placenta1. Chorion2. Allantois3. AmnionB. Placental AttachmentC. Functions of the Placenta1. Respiration2. Nutrition3. Waste Removal4. Protection5. Hormone ProductionIX. Reproduction- PregnancyA. Hormonal Changes During PregnancyCurrent Lecture: I. Uterus (3 parts): site for development of fetus (growth and nourishment)A. Uterine HornsB. Uterine Body1. Bicornuate (multiple feti): pig- small uterine body and large horns2. Bipartite (normally single fetus): horse, cow, ewe- large uterine body and smaller hornsC. Cervix (neck of uterus): primary function to keep uterus clean, only open during parturition (relaxin) and estrous (estrogen)- Thick walled- Collagenous rings (cow, ewe, sow) or folds (horse)- Site for semen deposition in sowII. Vagina: birth canal at parturition and site of semen deposition in cow and ewe- The Urethra from the bladder enters into the vagina floor near the vulvaA. Capacitation: maturation of sperm in the female reproductive tract, removal of surface componentsIII. Vulva: external portion of the female genitalia IV. Clitoris: has the same embryonic origin as the male penis- Highly innervated- Clitoral Massage: sometimes done with A.I. in cattle- May increase uterine motility- May synchronize LH surgeV. Reproduction- Ovarian CycleA. Follicles1. Primary Follicle: ovum surrounded by single layer of granulose cells 2. Secondary Follicle: granular cells increase in number through mitosis3. Tertiary Follicle: begin to see antrum formation 4. Gratian Follicle: mature follicle with mature ova, near ruptureB. Ovulation: surge of LH stimulates enzymes to digest follicle wall; ova releasedC. Corpus Luteum (CL- yellow body): granular cells produce progesterone- If not pregnant, CL regresses and forms corpus albicans (white body)D. Fertile Life of Ova and Sperm1. Ova- Cattle, sheep, pigs: 8-12 hours- Horses: 16-24 hours2. Sperm- Cattle, sheep, pigs: 24-48 hours- Horses: 72-120 hoursE. Fertilization: occurs at junction of ampulla and isthmus, results in zygote, cells divide about every 20 hours- First cleavage: 1 2 cell: occurs 24 hours after fertilization- 8 cell stage occurs within 2-3 days after fertilization- Passes into uterus 3-4 days after fertilization- Morula stage: 16-32 cells- Blastocyst: 5-8 days after fertilizationVI. Reproduction- Embryonic DevelopmentA. Blastocyst1. Inner cell mass: grows into fetusa. Endoderm: forms digestive tract, liver, lungs, and kidneysb. Mesoderm: forms muscle, bone, and fatc. Ectoderm: Forms skin, hair, brain, and spinal cord2. Trophoblast: forms placenta and embryonic membranes3. Blastocyst Cavity: fills with fluid VII. Reproduction- ImplantationA. Implantation- Blastocyst will loosely attach to wall of uterus- Embryo and uterine development must be in synchrony- If not the result is no implantation and embryonic death- Synchronizing the uterus and embryo is extremely critical in embryo transferB. Implantation TimesCow: 11-40 daysSheep: 10-22 daysPig: 12-24 daysHorse: 60-70 daysVIII. Reproduction- Placenta A. Placenta: three membranes that develop from the Trophoblast1. Chorion: outer membrane in contact with uterus2. Allantois: bridges outer/inner layers3. Amnion: inner membrane, closest proximity to embryoB. Placental Attachment1. Cotyledonary: Cow & Ewe2. Diffuse: Sow & Mare- Cotyledonary (fetal) + Caruncle (maternal) = placentome- Sheep: 90-100 placentomes- Cattle: 70-120 placentomes C. Functions of the Placenta1. Respiration: exchange of oxygen and carbon dioxide between fetus and dam2. Nutrition: transportation of sugars, amino acids, fatty acids, vitamins, and mineral from dam to fetus3. Waste Removal: exchange of waste products from fetus to dam4. Protection5. Hormone Production: estrogen and progesteroneIX. Reproduction- PregnancyA. Hormonal Changes During Pregnancy- If it is not pregnant: prostaglandin from uterus causes CL regression and cycle restarts- If pregnant: estrogen blocks prostaglandin production and CL continues progesterone production- In cow and sow: CL present through pregnancy- In ewe: CL needed for the 1st and 2nd trimester- In Horse: CL and progesterone present for the first 40 days, then the accessory CL through 150 days, then the placenta continues to produce progesterone for the remainder of
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