Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Pregnancy, Development, and Lactation Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Fertilization ____________: (act of breeding) intromission, thrusting, and ejaculation ____________: (act of breeding) intromission, thrusting, and ejaculation Copulation triggers _________ release from posterior pituitary gland of the female Copulation triggers _________ release from posterior pituitary gland of the female Oxytocin causes contraction of smooth muscle of the female reproductive organs Oxytocin causes contraction of smooth muscle of the female reproductive organs Semen is usually deposited in the upper portion of the __________ Semen is usually deposited in the upper portion of the __________ Spermatozoa transported by swimming, by contractions of uterus and oviducts, and by action of cilia in oviducts Spermatozoa transported by swimming, by contractions of uterus and oviducts, and by action of cilia in oviducts Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Fertilization _____________: series of changes spermatozoa undergo in the female reproductive tract to increase their chance of fertilization _____________: series of changes spermatozoa undergo in the female reproductive tract to increase their chance of fertilization 1. Change in ion movements (influx of Ca ++ ) through the cell membra 2. Increase in cells' metabolic rate 3. Increase in rate of sugar usage for energy 4. Release of digestive enzymes from _____________ Help spermatozoa penetrate layers Help spermatozoa penetrate layers around ovum to accomplish fertilization Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc.Fertilization Large number of spermatozoa locate and swarm around ovum in _____________ Large number of spermatozoa locate and swarm around ovum in _____________ Some begin tunneling through layers surrounding ovum Some begin tunneling through layers surrounding ovum Aided by digestive enzymes in acrosome Aided by digestive enzymes in acrosome Once a single spermatozoon penetrates cell membrane of ovum, the membrane blocks other sperm from entering Once a single spermatozoon penetrates cell membrane of ovum, the membrane blocks other sperm from entering Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc.Zygote ____________ a newly fertilized ovum. Male and female ___________ join together ____________ a newly fertilized ovum. Male and female ___________ join together Male pronucleus: nucleus of the fertilizing spermatozoon Male pronucleus: nucleus of the fertilizing spermatozoon Female pronucleus: nucleus of the fertilized ovum Female pronucleus: nucleus of the fertilized ovum Each pronucleus contains the haploid chromosome number Each pronucleus contains the haploid chromosome number Restores the ___________ chromosome number Restores the ___________ chromosome number Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Cleavage: Zygote to Blastocyst Rapid __________ of zygote (~1 division/day) Rapid __________ of zygote (~1 division/day) Overall size of zygote does not change Overall size of zygote does not change __________: solid mass of cells; stage after zygote __________: solid mass of cells; stage after zygote __________: hollow ball of cells with a mass of cells on one side (future embryo); stage after morula; will implant in uterus __________: hollow ball of cells with a mass of cells on one side (future embryo); stage after morula; will implant in uterus Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Implantation While cleavage is taking place, the zygote is slowly moving from the oviduct to the ___________ While cleavage is taking place, the zygote is slowly moving from the oviduct to the ___________ propelled by muscular contractions and cilia propelled by muscular contractions and cilia Enzymes produced by the blastocyst dissolve away a small ____ in the endometrium, where the blastocyst will attach Enzymes produced by the blastocyst dissolve away a small ____ in the endometrium, where the blastocyst will attach In _____________ species, the multiple blastocysts randomly space along the horns and body of the uterus In _____________ species, the multiple blastocysts randomly space along the horns and body of the uterus ____________ begins to form as soon as the blastocyst implants in the uterus ____________ begins to form as soon as the blastocyst implants in the uterus Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Placenta Multilayered, fluid-filled, membranous sac that surrounds the fetus and links it to the blood supply of the uterus Multilayered, fluid-filled, membranous sac that surrounds the fetus and links it to the blood supply of the uterus Outermost layer of placenta attaches to ________ _________ Outermost layer of placenta attaches to ________ _________ Fetal and maternal blood vessels are in close proximity to each other in this area Fetal and maternal blood vessels are in close proximity to each other in this area Site of exchange of blood, nutrients, and wastes Site of exchange of blood, nutrients, and wastes No direct contact between fetal and maternal blood occurs No direct contact between fetal and maternal blood occurs Connected to the fetus via the _________ ______ Connected to the fetus via the _________ ______ Umbilical ________: carries oxygen-rich blood to fetus Umbilical ________: carries oxygen-rich blood to fetus Umbilical ________: carry deoxygenated blood back to the placenta Umbilical ________: carry deoxygenated blood back to the placenta Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Placenta ________: membranous layer immediately surrounding the fetus ________: membranous layer immediately surrounding the fetus Forms the amniotic sac Forms the amniotic sac Fetus floats in amniotic fluid inside the amniotic sac Fetus floats in amniotic fluid inside the amniotic sac _________: layer surrounding amniotic sac; forms the allantoic sac _________: layer surrounding amniotic sac; forms the allantoic sac Outside of allantoic sac is covered by the chorion Outside of allantoic sac is covered by the chorion _________: attaches to lining of uterus _________: attaches to lining of uterus Chorion is linked to fetus by the umbilical cord Chorion is linked to fetus by the umbilical cord _________: tube that connects the bladder to the allantoic sac _________: tube that connects the bladder to the allantoic sac Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Placental Attachments 1. ___________: spread over the whole surface of the placenta and uterine lining (pigs, horses) 1. ____________: many small, separate attachment sites (placentomes) (ruminants) ____________: cotyledon on placental surface joins with caruncle in the uterine lining ____________: cotyledon on placental surface joins with caruncle in the uterine lining 2. ____________: belt-shaped attachment that encircles the placenta (dogs,cats) 3. __________: placenta and uterus attached at a single disk-shaped area (humans, primates, rabbits, rodents) Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Placental Attachments Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. _________ period: time from fertilization of ovum to delivery of newborn _________ period: time from fertilization of ovum to delivery of newborn Time varies among species Time varies among species Divided into three segments/trimesters Divided into three segments/trimesters First trimester: ____________ period First trimester: ____________ period Placenta develops Placenta develops Second trimester:__________ period Second trimester:__________ period Body tissues, organs, and systems develop Body tissues, organs, and systems develop Third trimester: fetal _________ period Third trimester: fetal _________ period SpeciesGestation Cat2 mo Cat2 mo Dog2 mo Dog2 mo Cow9 mo Cow9 mo Elephant21 mo Elephant21 mo Ferret6 w Ferret6 w Goat, Sheep5 mo Goat, Sheep5 mo Hamster3 w Hamster3 w Horse11 mo Horse11 mo Human 9 mo Human 9 mo Pig3 mo, 3 w, 3 d Pig3 mo, 3 w, 3 d Rabbit1 mo Rabbit1 moGestationPeriods Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc.Parturition __________ process __________ process Factors influencing parturition Factors influencing parturition Size and weight of uterus and fetus Size and weight of uterus and fetus Hormonal changes Hormonal changes Progesterone, fetal Cortisone causes mothers estrogen level to rise and Prostaglandin F 2 to be released from the uterine wall Progesterone, fetal Cortisone causes mothers estrogen level to rise and Prostaglandin F 2 to be released from the uterine wall The estrogen and prostaglandin increase the uterus sensitivity to oxytocin, which is now being released by the posterior pituitary The estrogen and prostaglandin increase the uterus sensitivity to oxytocin, which is now being released by the posterior pituitary Myometrium in uterus begins to contract due to the oxytocin, beginning labor Myometrium in uterus begins to contract due to the oxytocin, beginning labor Fetal changes at birth: Fetal changes at birth: _________ expand and begin to function _________ expand and begin to function foramen ovale and ductus arteriosus ___________ foramen ovale and ductus arteriosus ___________ Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Stages of Labor First stage - uterine contractions First stage - uterine contractions Myometrium contracts and presses fetus down against cervix Myometrium contracts and presses fetus down against cervix Sustained contractions cause cervix to gradually dilate Sustained contractions cause cervix to gradually dilate Second stage - delivery of newborn Second stage - delivery of newborn Results from combination of strong uterine and abdominal muscle contractions Results from combination of strong uterine and abdominal muscle contractions Rupture of amniotic and allantoic sacs of placenta usually precedes actual delivery of newborn Rupture of amniotic and allantoic sacs of placenta usually precedes actual delivery of newborn Third stage - delivery of the placenta Third stage - delivery of the placenta Placenta separates from wall of uterus and is expelled by weaker uterine contractions Placenta separates from wall of uterus and is expelled by weaker uterine contractions Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Involution of the Uterus Uterus gradually returns to nonpregnant size Uterus gradually returns to nonpregnant size Endometrium sloughs into lumen of uterus at sites of placental attachment Endometrium sloughs into lumen of uterus at sites of placental attachment Myometrium continues mild contractions to move remaining uterine contents out through birth canal Myometrium continues mild contractions to move remaining uterine contents out through birth canal May take from a few weeks to a month or more for involution to be complete May take from a few weeks to a month or more for involution to be complete Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mammary Glands Specialized skin glands that produce _________ and _______ Specialized skin glands that produce _________ and _______ Present in both male and female animals Present in both male and female animals Males do not secrete proper blend of hormones to make them work Males do not secrete proper blend of hormones to make them work Number and appearance of mammary glands differs among species Number and appearance of mammary glands differs among species Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Udder of Cow Four mammary glands (__________) Four mammary glands (__________) Quarters are completely separate units from each other Quarters are completely separate units from each other Each quarter has its own milk-secreting system and ducts leading down to separate teats Each quarter has its own milk-secreting system and ducts leading down to separate teats Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mammary _________: saclike arrangement of cells that secrete milk into alveolar duct Mammary _________: saclike arrangement of cells that secrete milk into alveolar duct Arranged like clusters of grapes around alveolar ducts Arranged like clusters of grapes around alveolar ducts Smaller alveolar _______ join to form larger ducts Smaller alveolar _______ join to form larger ducts Largest ducts empty into _______ sinus Largest ducts empty into _______ sinus located just dorsal to teat Continuous with ______ sinus inside teat Continuous with ______ sinus inside teat Milk accumulates in sinuses Milk accumulates in sinuses Alveoli and Duct System Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Milk Letdown Milk accumulates high up in mammary gland in alveoli and small ducts Milk accumulates high up in mammary gland in alveoli and small ducts Physical stimulation of nipple or teat sends sensory impulses that cause release of oxytocin from post. pituitary Physical stimulation of nipple or teat sends sensory impulses that cause release of oxytocin from post. pituitary Oxytocin causes contraction of ___________ cells around alveoli and small ducts Oxytocin causes contraction of ___________ cells around alveoli and small ducts Moves milk down into large ducts and sinuses Moves milk down into large ducts and sinuses Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mammary Gland Development Mammary glands develop in response to hormones produced at ____________ Mammary glands develop in response to hormones produced at ____________ Prolactin and GH directly encourage mammary gland development Prolactin and GH directly encourage mammary gland development Estrogen and progesterone produced by the ovaries during the estrous cycle encourage mammary alveoli and duct systems to develop. Estrogen and progesterone produced by the ovaries during the estrous cycle encourage mammary alveoli and duct systems to develop. TSH and ACTH can also promote mammary development TSH and ACTH can also promote mammary development Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Colostrum First milk First milk Pre-milk secretion Pre-milk secretion Imparts _________ __________- transfer of preformed __________ from dam to newborn Imparts _________ __________- transfer of preformed __________ from dam to newborn Supplies important nutrients to newborn Supplies important nutrients to newborn proteins, lipids, amino acids, and vitamins proteins, lipids, amino acids, and vitamins __________ effect helps clear meconium from newborn's intestinal tract __________ effect helps clear meconium from newborn's intestinal tract Mosby items and derived items 2008 by Mosby, Inc., an affiliate of Elsevier Inc.Lactation Physical stimulation of teat or nipple and regular removal of milk from gland stimulates ant. pituitary to continue production of hormones that keep lactation going Physical stimulation of teat or nipple and regular removal of milk from gland stimulates ant. pituitary to continue production of hormones that keep lactation going prolactin, oxytocin prolactin, oxytocin Lack of hormonal stimulation combined with increased pressure in the mammary gland gradually causes lactation to cease Lack of hormonal stimulation combined with increased pressure in the mammary gland gradually causes lactation to cease