20000301
Descripción
Fichas por Marissa Alvarez, actualizado hace más de 1 año
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Creado por Marissa Alvarez
hace alrededor de 5 años
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| Pregunta | Respuesta |
| The REPRODUCTIVE System Objectives: | •Review the unique relationship that the reproductive system has in regards to homeostasis •Examine the differences in anatomy of the male and female reproductive tracts, glands, gonads, and gametes •Contrast mitosis and meiosis •Explain sexual differentiation •Describe the three primary components of male reproduction •Examine the characteristics of spermatogenesis, along with the role of the Sertoli cells •Review testosterone synthesis and its conversion to active steroids in other tissues •Describe the actions of testosterone •Explain the regulation of testosterone •Review the control of luteinizing hormone and follicle-stimulating hormone secretion, with emphasis on gonadotropin-releasing hormone secretion |
| The reproductive system consists of the gonads, reproductive tract, and accessory sex glands. Reproduction depends on the ___ of male and female gametes. ->The reproductive systems of the two sexes are designed to enable this union. •The female system is also equipped to house and nourish the ___ developmentally until it is able to survive on its own. •___ reproductive organs produce gametes and secrete sex hormones: ->Male – __ (produce spermatozoa and secrete testosterone) ->Female - ovaries (produce ova and secrete estrogen and progesterone ) •A reproductive tract plus accessory ___ are found in either sex. •Unique ___ sexual characteristics are found in each sex. ->Differences in body configuration and distribution of body hair. ->Due to ___ in male and ___ in female. | union offspring Primary testis ovaries organs secondary testosterone estrogen |
| Functions and anatomy of the male reproductive tract: •Production of ___ (_____) •Delivery of ___ to the female | |
| Functions and anatomy of the female reproductive tract: •Production of ___ •Reception of ___ •___ of sperm and ova to a common site for union •Maintenance of the developing ___ •Parturition •Nourishing the infant | ova sperm Transport fetus |
| Reproductive cells each contain a HALF SET of chromosomes. Gametogenesis occurs by ____. –Cell division involves the division of the nucleus and the division of the ___. –___ is cell division that maintains the chromosome number, chromosome combination, and genetic identity of the chromosomes from the dividing parent cell to the two daughter cells produced. Mitosis produces ___ cells. –Meiosis produces ___. Only one chromosome from each chromosome pair is inherited in each of the four daughter cells produced from parent cells. The gametes have __-__ the chromosome number. | meiosis cytoplasm Mitosis somatic gametes one-half |
| Male & Female sex determination and sexual differentiation: ->Genetic sex depends on combination of ___ ____. ->Gonadal sex determined by presence or absence of ___ gene. ->Sex-determining region of Y chromosome (SRY) codes for production of ___-___ ___ (__) ->NO Y chromosome = NO __ & ___ ->TDF directs differentiation of gonads into ____ . ->With no TDF, undifferentiated gonads develop into ____ . | sex chromosomes SRY testis-determining factor (TDF) SRY & TDF testes ovaries |
| Male & Female sex determination and sexual differentiation: ->Testes secret testosterone and ___ ___ ___ (__). ->Mullerian-inhibiting factor leads to degeneration of ___ ___ . (this is in ___) ->Absence of Müllerian-Inhibiting factor leads to development of ___ ___ in females. ->Absence of testosterone leads to degeneration of ____ ___ . (this is in ___) ->____ sex determined by presence or absence of masculinizing hormones. | Mullerian-inhibiting factor (MIF) Mullerian ducts males Mullerian ducts Wolffian ducts females Phenotypic |
| External genitalia develops from the SAME embryonic tissue: Genital Tubercle = ___ tissue •Glans penis •Glans clitoris Urethral folds •Fuse to form ___ in male •Labia ___ in female Genital swellings •Fuse to form ___ and prepuce in males •Labia ___ in females *No dihydrotestosterone (DHT) = _____ *Presence of DHT = _____ | erotic penis minora scrotum majora female genitalia male genitalia |
| Reproductive tracts develop from DIFFERENT embryonic tissues: ->Mullerian ducts and Wolffian ducts are present in ___ sexes before sexual differentiation. Placental human chorionic gonadotropin stimulates: ->Testosterone – ___ Cells ->__ ___ ___ (__) – Sertoli Cells *Testosterone → __Wolffian ducts *MIF → ↓___ ducts ->Wolffian ducts differentiate into ___ reproductive tract ->Müllerian ducts differentiate into ___ reproductive tract. | both Leydig Mullerian Inhibiting Factor (MIF) ↑ Mullerian male female |
| ERRORS in sexual differentiation •If testes fail to properly differentiate → anatomic ___, but genetic ___ •___ ____ ____ = Genetic males whose target cells lack androgen receptors are feminized even though adequate testosterone is secreted •__-___ ___ = testosterone does not get converted to dihydrotestosterone (DHT) → genetic male with testes and male reproductive tract, but female genitalia •___ ___ = genetically female fetus that oversecretes DHEA can cause differentiation of the reproductive tract and external genitalia along male lines | female male Testicular feminization syndrome 5α-reductase deficiency Adrenogenital syndrome |
| REVIEW | |
| Male Reproductive Physiology Testes develop from the ___ ridge in the rear of the abdominal cavity. •During the last months of fetal life, the testes ___ from the abdominal cavity through the ___ canal into the scrotum. ->This movement is induced by ____ and usually complete by 7 months of gestation. •Incomplete closure of canal or rupture leads to an inguinal ___. •____ – undescended testicle(s) – bilateral or unilateral •The scrotum provides a ___ environment that is optimal for spermatogenesis (which cannot occur at ___ ___. A spinal reflex by scrotal muscles can retract the testes into the warmer abdomen. •The seminiferous tubules in the testis carry out _____. •___ cells in the testis secrete testosterone. Located in interstitial tissue between seminiferous tubules. | gonadal descend inguinal testosterone hernia Cryptorchidism cooler body temperature spermatogenesis Leydig |
| Light micrograph of the Semiiniferous Tubules | |
| EFFECTS OF TESTOSTERONE Prior to Birth: •Masculinizes the Reproductive tract and external genitalia •Causes ___ of the testes into scrotum •Secretion ___ after birth Effects on sex-specific tissues after birth (Puberty): •Growth and maturation of the entire ___ reproductive system: ->___ = period of arousal and maturation of a previously nonfunctional reproductive system to the point of being able to reproduce ->____ = entire transition between childhood and adulthood, not just sexual maturation •Spermatogenesis •Accessory sex glands ___ and become active •Penis and scrotum enlarge •Maintenance of reproductive tract through adulthood | descent ceases male Puberty Adolescence enlarge |
| EFFECTS OF TESTOSTERONE Other Reproduction Related Effects: •Development of sexual libido •Maintains sex ___ in adult male •___ feedback control of ___ - ___ ___ (___) (and thus luteinizing hormone & follicle-stimulating hormone) Effects on Secondary Sexual Characteristics: •All SSC depends on ____ •Male pattern hair growth, deepening of the voice, thickening of the skin, male body configuration | drive Negative gonadotropin-releasing hormone (GnRH) testosterone |
| Nonreproductive Actions of Testosterone: •___ to protein •Promotes bone growth •Terminating bone growth (epiphyseal plate closure) •May induce ____ behavior | Anabolic aggressive |
| Spermatogenesis: the production and development of mature spermatozoa The ___ ____ carry out spermatogenesis. | seminiferous tubules |
| Packaging of spermatids = _____ | spermiogenesis |
| Anatomy of spermatozoa Nucleus – ___ material ____ – enzymes, a modified lysosome produced by the endoplasmic reticulum-Golgi complex Tail powered by ___ concentrated in the midpiece. Cytoplasmic ___ b/w sperms cells during development allow necessary __ chromosome support for Y-bearing sperm. | genetic Acrosome mitochondria bridges X |
| SERTOLI Cell Functions Throughout sperm cell maturation, the cells are intimately associated with ___ cells in the wall of the ___ ____. The FUNCTIONS of the Sertoli cells: •____ junctions provide a blood-testes barrier •Prevent antibody formation against highly-differentiated spermatozoa •Provide nourishment via selective transport of materials through the blood-lumen barrier. Glut-1 transports ___ across where it’s converted to ___ for use by the sperm •Carry out ___ (engulf extruded cytoplasm, get rid of malformed germ cells) •Secrete a seminiferous tubule fluid which flushes sperm from lumen to ___ •Secrete androgen binding protein (maintains high __ within lumen). High luminal __ is essential for sustaining sperm production. __ also stimulates ABP production •Acted upon by testosterone and FSH to control ____, also secrete ___ to regulate FSH secretion •Secrete ___-___ factor | Sertoli seminiferous tubules Tight glucose lactate phagocytosis epididymis T T T spermatogenesis inhibin Mullerian-inhibiting |
| Gonadotropin-Releasing Hormone (GnRH): •increases at the time of ___ •Do NOT have receptors for ___ or ___ •___ neurons have receptors for androgens and estrogen •Increases to cause puberty: ->__ increase initially ->Involves __ neurons ->Likely involves other neuron types as well | puberty androgens or estrogens Kiss1 Nocturnal Kiss1 |
| ____ ____ Hormone: – enhances spermatogenesis, needed for remodeling ____ Hormone: – stimulates testosterone production from Leydig cells _______: -necessary for mitosis and meiosis -___ selectively inhibits FSH secretion from Sertoli cell | Follicle Stimulating Luteinizing Testosterone Inhibin |
| Remainder of Male Reproductive System Reproductive tract: -Accessory sex glands -Penis **All geared toward delivering ____ Epididymis: ->______ = the gaining of the ability to move and fertilize -Sperm are ____ of mobility or fertilization when they leave the testes. -stimulation by _____. -They gain further ability to do so in the ____ reproductive tract. ->_____ sperm 100x | sperm Capacitation incapable testosterone female CONCENTRTATES |
| Remainder of Male Reproductive System Reproductive tract: Ductus Deferens: •STORAGE ->Sperm can be stored for up to 2 months due to low ____ needs •Empties into the ____ •____ – ligation of the ductus or vas deferens | metabolic urethra Vasectomy |
| The male accessory sex glands contribute most to semen: ____: mixture of accessory sex gland secretions, sperm, and mucus SEMINAL VESICLES: –supplies ___ for energy (primary energy source) –secretes ____ for smooth muscle contraction in the tract of both male & females (transport) –provides most (about 60%) of the semen volume, washing the sperm into the urethra and diluting the thick mass of sperm, allowing ____ –secretes ___ (precursor of ___ needed for clotting, which keeps sperm in female reproductive tract) | Semen fructose prostaglandins motility fibrinogen fibrin |
| The male accessory sex glands contribute most to semen: _____ Gland: –secretes an alkaline fluid to neutralize the acidity of the female reproductive tract to increase sperm viability –provides clotting enzymes that act on fibrinogen to cause formation of ___ –Produces __ -___ ____ (PSA). This breaks down clot of sperm inside female reproductive tract, releasing sperm for ___. (Often measured as an index of potential cancer) –___ ___ ___ = enlarged prostate in older men –____ = vesicles that transfer components needed to maximize use of calcium for optimal motility and efficient fertilization ->____ Gland: Secretes a mucus-like substance for lubrication during sex | Prostate fibrin prostate-specific antigen movement Benign prostatic hypertrophy Prostasomes Bulbourethral |
| There are 4 phases to the male sexual response cycle: 1) _____ : -erection -testicular vasocongestion -heightened sexual awareness 2) _____ : -intensification -steadily increasing heart rate, blood pressure, respiratory rate & muscle tension 3) _____ : -ejaculation 4) ____ : return of genitalia and body systems to their pre arousal state | Excitement Plateau Orgasmic Resolution |
| Erection is accomplished by ____ of the penis with blood (____). (____ = increased pooling of blood, decreased venous drainage) | engorgement vasocongestion vasocongestion |
| Parasympathetic mediator – ___ ___ Erectile ____ (Impotence) -50% ages 40-70 -70% by age 70 Nitric Oxide -> Guanylate cyclase -> PDE5 cGMP breakdown -> Smooth muscle relaxation -> vasodilation -____ inhibits PDE5 cGMP breakdown **Parasympathetic supply to penile arterioles causes penile arterioles to ____, which leads to an erection (compressed veins). **NO used by PNS as a ____ | Nitric oxide (NO) Dysfunction Viagra dilate vasodilator |
| Ejaculation is the emission and expulsion of semen: Accomplished by a spinal ___ Occurs in two phases: 1) ___ – sympathetic impulses cause smooth muscle contractions in prostate, reproductive ducts, and seminal vesicles, thus delivering semen into the ___ 2) ____ - the expelling of the semen through the urethra. Filling of urethra triggers skeletal muscle ____ at base of penis. ->Female sexual cycle is similar except there is no counterpart to ejaculation and no ____ following orgasm •____ – Heavy breathing, high heart rate, generalized skeletal muscle contraction, intense pleasure & gratification •Resolution follows, including a refractory period of varying lengths, due to increased ___ input ->Average volume – 2.75 ml of 165 million sperm (<__ ___/ml - clinically infertile) | reflex Emission urethra Explulsion contraction refractoriness Orgasm SNS 20 million |
| REVIEW | |
| FEMALE REPRODUCTION Objectives | •Development of oocyte formation and differences between male and female gametogenesis •Define the hormonal underpinnings of the menstrual cycle •Define roles of estrogen and progesterone in cycle-associated changes in control of GnRH, LH, and FSH release •Examine how estrogen and progesterone influence the physiological state of the female reproductive tract •Define the role of estrogen and progesterone in sperm motility •Examine the process of fertilization and implantation •Examine placental and fetal development •Define mechanisms of parturition and the roles of various hormones •Examine hormonal involvement in lactation |
| General Male-Female Differences ->Unlike males, where sperm production is continuous and testosterone is relatively stable, release of ova is ___ & hormones display wide cycle-associated ___ in the female. •Menstrual cycle (menstruus = ___) ->Ovaries perform the dual function of producing ___ and secreting the female sex hormones (___, ___). •Like males, reproductive capability begins at ____ •Unlike males, it does NOT continue throughout life (____) | intermittent swings monthly ova estrogen, progesterone puberty menopause |
| By month 5 of gestation – 6 to 7 million ___ -Remain ___ oocytes from birth to puberty -Oocytes not incorporated into follicles undergo ____ -By birth – 2 million primary ___ -By puberty – 300,000 (primary follicles) -__ will mature and release ova -___ = degenerated follicle (99.97%) | oogonia primary apoptosis follicles 400 Atresia |
| Follicular phase about 14 days Luteal phase about 14 days | |
| 1) LH stimulates the ___ cells in the ovarian follicle. 2) On stimulation, the thecal cells convert cholesterol into ___. 3) Androgen diffuses from the thecal cells to the adjacent ___ cells. 4) FSH stimulates the ____ cells in the ovarian follicle. 5) On stimulation, the granulosa cells convert androgen into ___. 6a) Part of the estrogen is secreted into the ___, where it exerts systemic effects. 6b) Part of the estrogen remains within the ___ and contributes to ___ formation. 7) Local estrogen, along with __, stimulates proliferation of the ____ cells. | |
| FOLLICULAR PHASE Estrogen and inhibin, through actions at the pituitary, COMBINE to reduce ___-___ hormone secretion Estrogen NOT capable of fully suppressing ___ hormone release ->Kisspeptin neurons in the ___ ____ of the hypothalamus are targeted by ____ feedback Tonic secretion (___ & graded secretion) | follicle-stimulating luteinizing arcuate nucleus estrogenic slow |
| SURGE Secretion GnRH surge: •Stimulated by high ___ levels •Estrogen acts upon ___ kisspeptin neurons to stimulate gonadotropin-releasing hormone (GnRH) secretion •Estrogen acts upon the ___ pituitary to increase ____ hormone as well (relatively less for follicle-stimulating hormone) •____ still inhibiting follicle-stimulating hormone but there is a follicle-stimulating hormone surge as well Luteinizing Hormone Surge: 1. ___ estrogen synthesis 2. Reinitiates ___ 3. Triggers ___ release leading to rupture of cell wall 4. Conversion of follicular cells to ___ cell | estrogen AVPV anterior luteinizing Inhibin Halts meiosis prostaglandin luteal |
| LUTEAL PHASE Luteal Phase •Corpus luteum maintained by ___ hormone •Lots of ___ produced, less estrogen •Progesterone BLOCKS any positive effects of ____ on gonadotropin-releasing hormone secretion •_____ a very powerful inhibitor of gonadotropin-releasing hormone/___ hormone release •Factors underlying the demise of the corpus luteum are NOT completely known, but may involve prostaglandins, estradiol, and ___ LH secretion *Tonic secretion (slow & ___ secretion) | luteinizing progesterone estrogen Progesterone luteinizing decreased graded |
| 1 to 5, 24 •Antrum formation, ___ secreted in response to follicle-stimulating hormone and luteinizing hormone. •Rising ___ stimulates thickening of the endometrium. 6 to 8 •Circulating and antral concentrations of estradiol rise due to increasing levels of ___ hormone. •Estrogen and inhibin actions at the pituitary selectively lead to a decline in ___ -___ hormone. •Decline in follicle-stimulating hormone leads to ___ in all but the dominant follicle 9 to 11 •Rising estradiol triggers the ___ -____ hormone/____ hormone surge, causing ovulation and ___ levels to plummet. | estrogen estradiol luteinizing follicle-stimulating atresia gonadotropin-releasing/luteinizing estradiol |
| 12 to 17, 25 •Follicular cells are transformed to luteal cells and secrete ____ and, to a lesser extent, estradiol. •Progesterone strongly inhibits BOTH ___ hormone and ___-___ hormone. •Progesterone stimulates ___ vascularization and secretory activity of the endometrium. 18 to 23 •If NOT impregnated, the ___ ___ degenerates and progesterone and estradiol ___, allowing for an increase in ____ hormone and ___-___ hormone to begin the cycle again. •Withdrawal of progesterone & estradiol leads to ___ off of the uterine endometrium. | progesterone luteinizing follicle-stimulating increased corpus luteum decrease luteinizing follicle-stimulating sloughing |
| Changes in the uterus (menstrual cycle) occur with changes in ovarian hormones: •Estrogen stimulates ___ and myometrial growth. (Also stimulates ___ receptor expression in endometrium.) •Progesterone can then act on the estrogen-primed endometrium. –Lining becomes ___ and edematous due to accumulation of water and electrolytes –Stimulates endometrial glands to secrete and store ___ –Causes tremendous growth of endometrial ___ ___ –Reduces ____ of the uterus | endometrial progesterone loose glycogen blood vessels contractility |
| Changes in the uterus (menstrual cycle) occur with changes in ovarian hormones: MENSTRUAL PHASE −Characterized by ___ of blood and endometrium −Drop in hormone levels increases ___ release and ____ (and lack of O2) to the lining −PG also stimulates uterine ___. Prostaglandin ___production causes menstrual ____ (dysmenorrhea) −Blood clots in uterus then is broken down by ___ to flow out. −Contains large numbers of leukocytes (white blood cells) that play a role in helping the raw endometrium resist infection −Lasts about 5-7 days, concurrent with early ___ phase PROLIFERATIVE PHASE −Endometrium repairs itself and starts to proliferate due to ___ __ and ___ ___ hormone -induced estrogen secretion −Estrogen stimulates epithelium, glands, blood vessels SECRETORY/PROGESTATIONAL PHASE −After ovulation when a new corpus luteum is formed (luteal phase) −Corpus Luteum secretes large amounts of ___ & ____ −Progestational secretion of ___ into uterine lumen for nourishment of embryo | discharge prostaglandin vasoconstriction contractions over cramping fibrinolysin follicular LH- & FSH estrogen estrogen glycogen |
| Cyclical Changes in Cervical MUCUS: FOLLICULAR phase −Under the influence of ___, cervical mucus is clear, thin, and abundant −Most obvious when estrogen is highest (near ovulation) −Facilitates passage of ___ through the cervical canal •LUTEAL Phase −Mucus becomes thick and sticky −Essentially __ __ the cervical opening −This prevents ____ from entering the uterus from the vagina −Prevents sperm ___ | estrogen sperm plugs up bacteria penetration |
| PUBERTY −Changes are similar to those in males. −___ secretion increases at the onset of puberty. −GnRH stimulates the release of ___ hormone from the anterior pituitary, first occurring at ___ . −Doesn’t involve ___. The role of ___ is at least permissive. −____ release promotes many changes in the female reproductive system and in other body characteristics (fat deposition in breasts, buttocks and thighs) & eventually the preovulatory surge. (Also closes ____ ___). −Growth of axillary and pubic hair, pubertal growth spurt, development of libido due to increase in adrenal ____ | GnRH luteinizing night melatonin leptin Estrogen epiphyseal plates androgens |
| MENOPAUSE −Unique to females −May involve depletion of ___, may involve hypothalamic dysfunction −Preceded by a period of increasingly ___ cycles and ___ estrogen levels (climacteric or perimenopausal period) −Potential ____ −Hot flashes, may be due to increased ___ ___ secretion at surface vessels | ova irregular decreasing nitric oxide osteoporosis |
| Fertilization normally occurs in the __ __ of the oviduct (___). •Fertilization must occur within __ hours after ovulation. If not, the ovum ___. •Sperm cells normally survive for ~ _ days in the female reproductive tract, but can last up to _. (Sperm deposited from 5 days prior to 24 hrs after ovulation may fertilize ova) •___ pregnancy can occur when it doesn’t enter the oviduct or stays in oviduct | upper third ampulla 24 disintegrates 2 5 Ectopic |
| Sperm migration is aided by the female tract/ovum: −____ of cervical mucus (due to high ___ near the time of ovulation) allows passage into the uterus. Sperm get through cervix under their own ___. −contractions of the uterine myometrium (smooth muscle layer) distribute sperm throughout ___ lumen. Stimulated by high ___ and seminal ___ −____ contractions of the oviduct (induced by estrogen and prostaglandins) propel sperm to site of fertilization, fimbriae (cilia) in oviduct | Thinning estrogen power uterine estrogen prostaglandins antiperistaltic |
| Sperm migration is aided by the female tract/ovum. -hOR17-4, ___ receptor on sperm that is attracted to ____, a chemoattractant produced by the corona radiata. -Binding increases intracellular ___ release, allowing for increased swimming. −____ released by cells around the ovum also serve as a chemoattractant. It binds to surface membrane receptors and opens calcium-permeable cation channels (___) in the ___ of the sperm. ->Increase in calcium causes: 1. ____ of sperm 2. Hyperactivated ____ which provides sperm with increased power needed to penetrate the corona radiata and zona pellucida 3. ___ reaction | olfactory bourgeonal calcium Progesterone CatSper tail Capacitation motility Acrosome |
| Increased intraovum Ca2+ also causes the ___ meiotic division Sperm activates ovum enzymes essential for early ___ development Penetration of corona radiata by sperm: binding of __ receptors by ___ Acrosome reaction: triggered by ___ binding | second embryonic ZP3 fertilin ZP3 |
| REVIEW | |
| ->_____ from corpus luteum stimulates glycogen release from endometrium and ____ oviduct allowing for zygote to be expelled into ___ lumen ->Time allows for necessary nutrients to accumulate in uterine ____ | Progesterone relaxes uterine lumen |
| ->____ and uterine lining become “sticky” through expression of cell adhesion molecules ->_____ makes a hole via enzymatic breakdown, but also makes nutrients available for blastocyst ->Area of uterus that undergoes changes to accept blastocyst = _____ -Local ____ release increases vascularity, causes edema, and enhances nutrient storage | Blastocyst Trophoblast Decidua prostaglandin |
| Acceptance of Fetus by Mother; fetus is actually a FOREIGN object ___ natural killer cells are unable to kill fetal cells (unlike the usual natural killer cells) ->lock decidual dendritic cells in a ___ producing state ->dNK’s and DDC’s induce apoptosis of maternal __ _ cells ->promote production of regulatory T cells •____ cells produce a unique Class 1 MHC glycoprotein that allows them to evade interaction with killer cells •Trophoblastic cells produce ___ ligand ->Binds fas ->Fas is a specialized receptor on the surface of activated maternal ___ _ cells (immune cells that destroy foreign cells) ->Binding triggers ___ of T cells •Fetal portion of placenta produces indoleamine 2,3 dioxygenase (___): ->Destroys ____ ->Tryptophan is critical for ___ of cytotoxic T cells •Production of ___ T cells is doubled or tripled ->____ T cells ___ cytotoxic T cells | Decidual tolerance cytotoxic T Trophoblastic Fas cytotoxic T apoptosis IDO tryptophan activation Regulatory regulatory suppress |
| The placenta is the organ of exchange b/w the maternal and fetal blood. •Glycogen from endometrium is sufficient only for a ___ weeks •___ – begins when trophoblast layer is 2-cells thick. •As chorion ____, it forms cavities within ___ into which maternal blood leaks. Blood is kept from clotting via an ____ produced by the chorion. •Fingerlike projections of the chorionic tissue form placental ___ that extend into these pools of maternal blood. •Fetal ___ project into the placental villi. Fetal and maternal blood are separated here by a thin ___ layer. •Exchange occurs b/w the maternal and fetal blood. •Fetal blood leaves through an ___ vein. •Maternal blood exits through maternal ____. In place & operational by __ weeks after implantation | few Chorion expands decidua anticoagulant villi capillaries chorionic umbilical venules 5 |
| Functions of the Placenta •Digestion, Respiration, Kidneys: ->Nutrients and __ move from maternal blood to fetus ->___ and other metabolic wastes move from fetus to maternal blood •Different substances cross in different ways: ->simple diffusion, facilitated diffusion, secondary active transport, receptor-mediated endocytosis •Many unwanted substances can also cross ->_____ = tranquilizer that caused limbless babies ->Heroin and other drugs lead to addicted babies ->Aspirin, alcohol, agents in cigarette smoke ->AIDS virus •Placenta is also an ____ organ | O2 CO2 Thalidomide endocrine |
| •Human chorionic gonadotropin (__) maintains the ___ ___ of pregnancy by acting in the place of ___ hormone. •Normal ___ hormone secretion reduced by continuing ___ secretion. •Human chorionic gonadotropin stimulates ___ ___ production of testosterone in the male fetus. •Human chorionic gonadotropin (HCG) eliminated in the ___ and forms the basis for early detection of ___ (about two weeks following missed menstrual period). | HCG corpus luteum luteinizing luteinizing progesterone Leydig cell urine pregnancy |
| ->Estrogen not produced by placenta __ on because it lacks the enzymes needed to make it and thus has to wait on the fetal adrenal to develop the ability to produce ___. -Major estrogen produced is ___, which can only be produced from fetal ___, so estriol in mother’s urine can be used as an index of fetal viability Lack of early progesterone production due to ___ mass of placenta Estrogen: 1. Grows the ___ 2. Promotes development of ducts in mammary glands Progesterone: 3. Prevent ___ by suppressing myometrial contractions 4. Promotes __ formation in cervix 5. Stimulates the development of milk glands | early DHEA estriol DHEA small myometrium miscarriage plug |
| Changes in later gestation prepare for parturition. *Parturition is ___. During the last trimester the uterus becomes more excitable. Mild contractions occur (___-___ contractions). •The cervix begins to soften near parturition due at least in part to the effects of ___. •The fetus shifts downward, with its head contacting the cervix. •Rhythmic contractions begin at the onset of ___. There are high levels of ___ at this time. ->Estrogen increases connexons within uterine smooth muscle cells. Form ___ junctions b/w cells that allow them to be electrically linked for coordinated contractions ->Estrogen increases myometrial receptors for ____. ->Estrogen stimulates increased local ____ production to promote cervical ripening (degradation of ___). These prostaglandins also increase uterine responsiveness to ___. •Factors triggering the onset of parturition are not well understood. | Birth Braxton-Hicks relaxin labor estrogen gap oxytocin prostaglandin collagen oxytocin |
| PARTUITION DIAGRAM | |
| Uterine Involution: ->Return of the uterus to ____ state (4-6 weeks) ->Due to loss of ___ and ___ support ->Breast feeding hastens process due to release of ___ that causes uterine ____ 1.) First stage of labor Cervical ____ 2.) Second stage of labor: ___ of baby 3.) Third stage of labor:Delivery of ____ | prepregnancy estrogen progesterone oxytocin contractions dilation Delivery placenta |
| •Milk synthesized in ___ epithelial cells, secreted into the alveolar lumen, and ejected into a milk duct that leads to the nipple •Estrogen promotes ___ development •____ promotes alveolar-lobule development •Prolactin and human ___ ______ (__) induce synthesis of enzymes for making milk & also promote growth of the fetus through stimulation of IGF-1 & IGF-2 ->Breasts are capable of lactation by ___ through pregnancy. High ___ and P block prolactin from causing milk release. Thus, the drop in E and P initiate lactation. | alveolar duct Progesterone chorionic sommatomammotropin (hCS) IGF-1 and IGF-2 midway estrogen |
| SUCKLING REFLEXES | |
| Advantages of Breast Feeding: For the infant: -Nutrients (water, fat, lactose, proteins, vitamins, Ca2+, PO4) -Contains a host of immune cells (particularly the ___ – milk produced in the first 5 days) -Secretory __ = protect against infectious microbes that the infant is most likely to encounter -___ : may bind to and prevent uptake of harmful microorganisms through the intestinal wall -___ = decreases availability of iron to harmful bacteria -Bifidus factor = promotes growth of lactobacillus bifidus, which helps crowd out harmful bacteria -Other factors promote maturation of the digestive tract For the mother: ->Hastening of uterine involution ->Suppression of menstrual cycle (perhaps through prolactin) *Milk production stops at weaning due to the lack of ___ stimulation. | colostrum IgA Mucus Lactoferrin suckling |
| REVIEW |
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