ANSC 107 1nd Edition Lecture 16 I II I II Outline of previous lecture Growth Hormones a Endogenous peptide b Endogenous steroid c Anabolic steroids Outline of current lecture Male reproductive system a Organs b Functions c Structures Female reproductive system a Functions b Anatomy Male reproduction system Reproductive organs o Vas deferens o Retractor penis muscle These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Causes extension of penis o Glands penis o Scrotum o Testes o Caput epididymis head o Cauda epididymis Tail Function of the male Produce and maintain supply of sperm o Termed spermatogenesis Detect females in estrus o Using pheromones visual cues Inseminate females and fertilize the female gamete o 60 days for sperm cell to produce Structure of Testes spermatic cord contains vas deferens pampiniform plexus and external cremaster muscle nerves vas deferens transport sperm during ejaculation seminiferous tubule sperm producing cells true germinal epithelium corpus epididymis maturation of spermatozoa cauda epididymis final maturation and storage only sperm capable of fertilization rete testis function in sperm transport from seminiferous tubules 100 tubules Tunica albuginea connective tissue which hold testis together Efferent ductules 6 12 tubules absorb fluid Caput epididymis function in maturation of spermatozoa fluid absorption Structures within Cells Sertoli cells support spermatogenesis Leydig cells testosterone synthesis Increasing maturity o spermatogonium o Primary spermatocyte o Secondary spermatocyte o Spermatids Function of Testes Produce sperm o Sertoli cells are involved with control of development Transport sperm out of testes o Not transported by sperm motility Testis capsule tunica albuginea causes pressure with some smooth muscle contraction Seminiferous tubules myoid cells contract to move spermatozoa Efferent ductules and caput water absorption causing the sperm to be drawn toward the epididymis Produce testosterone o Leydig cells stimulated by LH luteinizing hormone from anterior pituitary o Testosterone function Maintain libido male sex drive Stimulates secondary sex characteristics muscle development accessory glands Maintain function of male reproductive tract Penis and muscles for ejaculation Thermoregulation of testis Temperature 3 5 C less than body temperature are required for spermatogenesis to occur 1st major factor of scrotum Scrotal properties that facilitate thermoregulation Location of testies outside away from body air circulation Low insulation thin skin low subcutaneous fat or hair Sweat gland richly endowed evaporative cooling Tunica dartos smooth muscle which lines scrotal wall o Change in testis location vary closeness to body wall o Change in scrotal area vary in thickness nd 2 major factor Blood supply to testis Pampiniform plexus o Countercurrent heat exchange causes a cooling of arterial blood supply o Single artery surrounded by a network of veins Convoluted testicular artery on surface of testis o In ram temperatures decrease before entering testis o Scrotum testis and spermatic cord are all involved in thermoregulation Cyptorchidism o Lack of testis descent into scrotum and thus thermoregulation is absent o Bilateral is sterile No spermatogenesis Testosterone is produced o Unilateral is fertile Reduce sperm producing capacity o Common in oars and stallion Testis descend late Function of epididymis Storage of sperm CAUDA o Only approximately sperm produced make it to this point o 70 of sperm in Cauda o Major site of sperm numbers in excurrent outside testis ducts 2 in vas deferens o Four days of testicular sperm produce is stored Can be stored for several weeks o Stored without loss of function o Arrest sperm metabolism sperm doesn t burn out o Allows for repetitive ejaculations of a short period o Sperm are indefinitely viable as prolonged sexual rest results in the first couple of collections showing poor sperm quality Fate of unejaculated sperm Reabsorbed by excurrent duct system o Epididymis Vas deferens and ampulla o Some selective removal of abnormal sperm in epididymis macrophages Sperm lost in urine 87 o 87 of daily sperm from epididymis of inactive ram are found in urine Masturbation loss of sperm o Management problem in boars and stallions Volume and sperm concentration are inversely relate Breeding Soundness exam BSE Fertility o Motility o Morphology Body condition Feet Female reproductive system Overall functions for the female reproductive tract Control activity of organs hormonal o Endocrine function o Ovary uterus fetus placenta pituitary i e estrus stimulation of myometrial contractions transport sperm o stimulation of myometrial contractions produce oocyte o female gamete haploid facilitate fertilization o sperm passage from uterus to oviduct provide environment for embryo and fetus o early oviduct uterus the remainder of pregnancy give birth to fetus o dilation of cervix strong uterine contractions Recycle to become pregnant again o involution of uterus return to positive energy balance Reproductive anatomy Vulva o Passageway for urine o Receptor for penis during copulation o Passageway for fetus Vagina o Female organ of copulation at mating o Birth canal at parturition o Mucosal surface that changes during estrous cycle Cervix o Thick wall extension of uterus o Passageway for sperm following breeding o Secrets mucous seal off uterus during pregnancy o Passageway of fetus o Species specific Cow has 4 5 annular rings Sow corkscrew o Functions Sperm barrier in cow and ewe Transport sperm Reservoir for sperm Block bacterial invasions Birth canal Uterus womb o Incubator fertilized ovum o Gives nutrients to ovum o o o o Aids travel of sperm Secretory organ Has two horn or branches Components Horns Two cornua Pig length 4 5 in Cow 7 8 in o Functions Transport sperm Muscle contractions Sperm motility Absorption and phagocytosis Partially prepares sperm for fertilization Provides environment for embryo Supports development of fetus At birth expels fetus Recovers from pregnancy o If not pregnant Uterine endometrium releases prostaglandin to cause the CL to regress o Interferon tau pregnancy recognition Allows CL to be maintained Oviduct o Open ended tube from are of ovary to uterus o Passageway for sperm and ovum o Site of fertilization o Takes 3 5 day for ovum to travel down uterus o Functions Transport sperm to