Term
| levels of sexual differentiation |
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Definition
| establishment of genetic sex, differentiation of gonads, differentiation of internal reproductive structures, differentiation of external genitalia, gender role, and gender identity |
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Term
| role of testosterone in differentiating internal ducts |
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Definition
| Wolffian duct regresses in its absence and proliferates in its presence, fetus becomes male |
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Term
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Definition
| sex-determining gene on the Y chromosome, master switch of sex determination, encodes high mobility group (HMG) transcription factors, also called testis determining factor |
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Term
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Definition
| pure gonadal dysgenesis, karyotype is XY, individual develops as female externally, no puberty, gonads typically removed due to predisposition of tumor development, treatment is estrogen/progesterone therapy |
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Term
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Definition
| translocation of SRY region of Y chromosome to X chromosome causes it |
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Term
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Definition
| one of most common sex chromosome disorders, XXY karyotype, inhibition of testicular development, reduced fertility, poor facial/chest hair growth, breast development, wide hips, pubic hair pattern is more female, individuals tend to have developmental or behavioral problems |
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Term
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Definition
| absolutely essential at normal levels to differentiate male genitalia |
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Term
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Definition
| converts testosterone to DHT |
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Term
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Definition
| gender presented by individual to society, can be completely independent of genetic/anatomical sex, includes traits such as: name, dress, physical appearance, family role, occupation, and behavior |
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Term
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Definition
| internal conviction of one's gender, inner sense of "male- or femaleness," poorly understood, argument of nature vs. nurture |
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Term
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Definition
| sequence of hormonal regulatory elements involving hypothalamus, anterior pituitary, and gonads, involves higher brain centers |
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Term
| hypothalamus' role in HPG axis |
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Definition
| releases gonadotropin releasing hormone |
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Term
| anterior pituitary's role in HPG axis |
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Definition
| GnRH released from hypothalamus triggers LH and FSH release |
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Term
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Definition
| secrete sex steroids and peptide hormones, act as site of germ cell production and maturation |
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Term
| negative feedback from Sertoli cells |
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Definition
| make inhibin when sperm count gets high, acts on anterior pituitary |
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Term
| negative feedback from Leydig cells |
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Definition
| testosterone (triggers spermatogenesis) acts on anterior pituitary and hypothalamus |
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Term
| ovarian feedback on HPG axis |
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Definition
| estrogen and progesterone exert negative influence during luteal phase on anterior pituitary and hypothalamus and positive influence on both during follicular phase |
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Term
| higher center input on HPG axis |
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Definition
| neurons controlling GnRH secretion receive stimuli from stress, emotion, visual/olfactory input |
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Term
| neurotransmitters affecting HPG axis |
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Definition
| norepinephrine, epinephrine, dopamine, acetylcholine, endorphins/opioids, neuropeptide Y, leptin, serotonin, cholecystokinin, and GABA (major inhibitory one) |
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Term
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Definition
| neurons producing it are found in arcuate nucleus of mesiobasal hypothalamus, stored in granules, secreted in pulses every 70-90 minutes, has very brief half-life |
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Term
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Definition
| produced by anterior pituitary, have identical alpha subunit and unique beta subunits, regulated by hypothalamic GnRH and feedback from gonadal hormones |
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Term
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Definition
| exact trigger unknown, influenced by: genetics, nutrition, weight, skeletal maturation, altitude, psychosocial/environmental factors; occurs when HPG axis matures |
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Term
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Definition
| re-activation of HPG axis in first few months of life, testosterone levels equal those of adult, no physical consequence, function unknown |
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Term
| changes at puberty of HPG axis |
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Definition
| decreased sensitivity to negative feedback, increased pulsatile GnRH secretion, increased sensitivity of pituitary gonadotrophs, increased LH/FSH secretion, increased responsiveness of gonads, increased gonadal steroid production |
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Term
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Definition
| stimulates release of hypothalamic GnRH, ligand of GPR54 |
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Term
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Definition
| 7 transmembrane domain receptor, mutations in it cause hypogonadotropic hypogonadism, expressed by GnRH neurons |
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Term
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Definition
| onset of adrenal androgen production, occurs 2-3 years prior to puberty at ages 7-8, INDEPENDENT of gonadal production of sex steroids |
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Term
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Definition
| onset of breast bud development, estrogen-induced, average onset 10.8 years in US |
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Term
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Definition
| onset of pubic hair growth, influenced by estrogen or testosterone, 11 in females, 11.6 in males |
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Term
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Definition
| rise in gonadal sex steroids as result of HPG axis activation |
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Term
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Definition
| growth acceleration, skeletal maturation, genital changes |
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Term
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Definition
| 2-2.5 years after onset of puberty, 1st menses |
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Term
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Definition
| age is 9-14, first sign is testicular enlargement, peak of growth is 2 years after girls |
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Term
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Definition
| secondary sexual development before 7.5 in girls and 9 in boys, categories are: normal variants, central, and peripheral |
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Term
| central precocious puberty |
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Definition
| majority of cases of abnormal development, same physiology as normal route but earlier, more common in girls, any form of CNS insult increases risk, gradual secondary sexual development, potentially compromises adult height |
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Term
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Definition
| high levels of sex hormones are produced, cause may be tumor in adrenal gland or ovary/testis, sex glands do not mature but child appears adult-like |
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Term
| peripheral precocious puberty |
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Definition
| abnormal source of sex steroids, rare, source of steroids endogenous or exogenous, often has acute onset |
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Term
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Definition
| caused by activating mutation in G-protein signaling, elevated cAMP in endocrine tissue, triad of precocious puberty/cafe-au-lait birthmarks/fibrous bone dysplasia, causes ovarian cysts in girls, somatic mutation in a mosaic distribution |
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Term
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Definition
| failure of onset by 13 in girls or 14 in boys, can be normal genetic variant or pathological (anywhere in HPG axis) |
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Term
| characteristics of testes |
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Definition
| dual function (spermatogenesis and steroidogenesis), is site of sperm and testosterone production, comprised of germ cells/Sertoli cells/Leydig cells |
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Term
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Definition
| created by tight junctions between Sertoli cells, prevents immune attack on spermatocytes |
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Term
| Sertoli supportive functions |
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Definition
| support gametes, phagocytose damaged cells, assist spermiation by proteolytic action of plasmin, synthesize transferrin |
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Term
| Sertoli cell secretory functions |
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Definition
| contain FSH receptors (linked to G-protein), produce androgen binding protein/inhibin/plasminogen activator |
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Term
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Definition
| made by Sertoli cells, negative feedback for FSH, has paracrine actions |
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Term
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Definition
| contain LH receptors, stimulate steroidogenesis, produce testosterone |
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Term
| Sertoli-Leydig interactions |
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Definition
| testosterone diffuses from Leydig to Sertoli cells, Sertoli cells aromatize testosterone to estradiol, estradiol diffuses back to Leydig cells |
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Term
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Definition
| opioids, AVP, oxytocin, GnRH-like peptide, growth factors, and neurotransmitters |
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Term
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Definition
| 3 distinct phases: mitosis, meiosis, spermiogenesis; 200 million/day, takes 60-70 days, "wave" ensures uninterrupted supply of sperm |
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Term
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Definition
| differentiation of spermatid to spermatozoa, "axoneme" formed, "acrosome" covers nucleus |
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Term
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Definition
| made of head, middle piece (energy supply), tail (microtubules surrounded by fibrous sheath) |
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Term
| testosterone in spermiogenesis |
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Definition
| allows capacitation in the epididymis |
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Term
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Definition
| 2-5 mL, 10% sperm by volume, secretions from accessory glands, made up of fructose, ascorbic acid, prostaglandins, and fibrinolysin |
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Term
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Definition
| occurs in 2 phases: emission (movement into urethra by lumbar spinal nerves and smooth muscles) and ejaculation (spinal reflex mechanism) |
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Term
| testicular steroidogenesis |
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Definition
| pathway exists in multiple tissues, relative products depend on which enzymes are predominant, pregnenolone is key intermediate |
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Term
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Definition
| stimulates testosterone synthesis via G-protein mediated cAMP formation w/ activation of PKA, has high affinity on Leydig cell |
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Term
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Definition
| familial male limited precocious puberty at 2-6 years, caused by heterozygous missense mutation in LH receptor, treated w/ androgen receptor blocker and aromatase inhibitor |
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Term
| metabolism of testosterone |
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Definition
| immediately diffuses into blood after formation, majority circulates in bound form, most converted to DHT or estradiol |
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Term
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Definition
| metabolized from testosterone by 5-alpha reductase (which is also active in hair follicles/sebaceous glands), 2-3x more potent, critical for normal differentiation |
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Term
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Definition
| aromatization occurs in many tissues (including brain), levels approach those in women during follicular phase, abnormal ratio compared to T causes gynecomastia |
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Term
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Definition
| responsible for: sexual differentiation, secondary characteristic development, mediation of hair growth and balding, lipid levels, RBC mass, and masculinization of the brain |
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Term
| androgen effects on brain |
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Definition
| controls hierarchy, mating/copulatory behaviors; no correlation between hormone levels and libido |
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Term
| disorders of male reproduction |
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Definition
| 50% of infertility due to endocrine disorders, Kallmann syndrome, primary hypogonadism, and other endocrinopathy |
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Term
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Definition
| caused by mutations within KAL gene, results in hypogonadotropic hypogonadism and anosmia (due to failure of migration of GnRH-secreting neurons from olfactory placode to hypothalamus) |
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Term
| hypothalamic-pituitary-ovarian axis |
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Definition
| axis in females, hormone secretion is cyclic and highly synchronized, steroidal feedback is both positive and negative |
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Term
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Definition
| site of germ cell maturation and steroidogenesis in females, produces estrogen/progesterone/inhibin |
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Term
| reproductive ducts in females |
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Definition
| responsible for transportation of ova and maintenance of conceptus during pregnancy |
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Term
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Definition
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Term
| progesterone production site |
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Definition
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Term
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Definition
| progression from primordial follicle to mature follicle |
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Term
| FSH role in folliculogenesis |
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Definition
| stimulates granulosa cell estradiol production, granulosa cell mitosis (and in turn enhancement of positive feedback), and hormone itself is important constituent of liquor folliculi |
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Term
| gonadotropin dependence of follicles |
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Definition
| during primordial stage: independent, beyond primary stage: dependent |
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Term
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Definition
| requires coordination between granulosa and theca cells and LH/FSH, primary product is estradiol from precursors |
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Term
| granulosa cell characteristics |
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Definition
| only cell type containing FSH receptors in female, depends on androgens from theca cells, has LH receptors in mature follicle |
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Term
| theca cell characteristics |
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Definition
| cell containing LH receptors, have access to circulating cholesterol, produce androgens |
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Term
| LH surge effects on dominant follicle |
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Definition
| this hormone triggers resumption of meiosis (which inhibits oocyte maturation factor), increases blood flow, activates proteolytic enzymes, shifts steroidogenesis towards progesterone, causes follicular rupture 30-36 hours after onset |
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Term
| events prior to ovulation |
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Definition
| basement membrane disintegrates, granulosa cells undergo luteinization (become vascular and lipid rich), plasmin degrades follicular wall |
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Term
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Definition
| results from steroid withdrawal from corpus luteum regression, has follicular/luteal/menses phases |
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Term
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Definition
| at this point, steroid hormones drop and FSH levels rise |
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Term
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Definition
| at this point estradiol levels increase and peak on day 12, estradiol exhibits positive feedback on LH release |
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Term
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Definition
| at this point, steroid levels are rising due to corpus luteum; begin to fall when CL fails, which triggers next stage and repeat of cycle |
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Term
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Definition
| occurs at same time as follicular phase in ovary, endometrium hypertrophies, spiral arteries form |
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Term
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Definition
| begins in uterus at ovulation, uterine glands coil/secrete mucus, arteries become tortuous |
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Term
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Definition
| occurs when corpus luteum fails, results in necrosis of uterine mucosa, blood supply decreases, prostaglandins are released |
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Term
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Definition
| occurs in uterus, desquamation of functional layer of endometrium |
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Term
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Definition
| in humans only, happens when oocyte supply is exhausted, gonadotropins increase, stromal cells continue to produce androstenedione, decreased estrogen results in: hot flashes, decreased bone mass, increased cardiovascular risk, and atrophy of vaginal epithelium |
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Term
| major abnormalities of female reproduction |
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Definition
| primary and secondary amenorrhea, infertility |
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Term
| severe primary hypothyroidism in children |
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Definition
| causes precocious puberty, due to cross-reactivity of TSH at FSH receptor, remits with proper treatment of primary problem |
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Term
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Definition
| failure of menses to occur at 16; can be result of decreased/inhibited GnRH secretion (affects pulsatile release of LH/FSH), gonadal dysgenesis (streak gonads in Turner syndrome), or disorder of sex development |
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Term
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Definition
| rate of 1:2500, missing or structurally abnormal X chromosome, characteristics are: short stature, accelerated ovarian atresia, delayed puberty/primary amenorrhea |
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Term
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Definition
| happens after menses already start, temporary absence; caused by pregnancy, endocrine disorders (hypo/hyperthyroidism, hyperprolactinemia, non-classic CAH), polycystic ovarian syndrome, or anorexia |
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Term
| polycystic ovary syndrome |
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Definition
| most common reproductive abnormality in women, increased androgen production but no ovulation, obesity and hirsutism are common features, unifying feature is insulin resistance |
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Term
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Definition
| requires rapid transport of both germ cells, facilitated by female reproductive tract, head adheres to zona pellucida through ZP3, acrosome reaction is triggered (dissolves cumulus and penetrates ZP), sperm crosses perivitelline space, adheres to oolemma, head/tail engulfed |
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Term
| implantation of blastocyst |
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Definition
| occurs in uterus 7 days after fertilization, proteases from trophoblast cells mediate endometrial invasion, conversion of trophoblasts takes place, dilation of endometrial blood vessels, lacunae appear, villi from embryo establish functional communication between vascular systems |
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Term
| fertilization events following sperm penetration |
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Definition
| cortical granules are released and fuse w/ oolema over entire surface, zona reaction prevents polyspermy, intracellular Ca2+ increase triggers 2nd meiotic division, pronuclei fuse and form zygote |
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Term
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Definition
| 20-30 cell stage of embryo, fluid-filled cavity with trophoblast (embryonic part of placenta) and inner embryoblast (fetus), will attach to uterine wall |
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Term
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Definition
| product of transformation of endometrium occurring at implantation, requires progesterone from CL |
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Term
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Definition
| condition in which cells proliferate inappropriately, hormonally influenced, main symptom is pelvic pain, is a common cause of infertility |
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Term
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Definition
| maternal and fetal components interdigitate, hemochoroidal (maternal blood bathes endothelium and connective tissue) |
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Term
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Definition
| encloses fetus, thin avascular membrane w/ amniotic fluid |
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Term
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Definition
| adjacent layer to amnion, encloses fetus |
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Term
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Definition
| delivery of nutrients/oxygen/carbon dioxide, removal of waste, pinocytosis/diffusion of glucose/AAs/electrolytes/hormones |
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Term
| placenta as endocrine organ |
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Definition
| produces progesterone, estrogen, human chorionic gonadotropin, human placental lactogen, and other peptides |
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Term
| human chorionic gonadotropin |
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Definition
| trophoblast cells of embryonic placenta produce it, extends life of corpus luteum, first sign of pregnancy 7-10 days post-fertilization, is a glycoprotein comprised of alpha and beta subunits, structurally similar to LH, stimulates progesterone production by CL, may have critical role throughout pregnancy |
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Term
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Definition
| has lactogenic and growth hormone-like actions, secreted by suncytiotrophoblasts, main function is to alter fuel availability (antagonizes maternal glucose consumption, mobilizes fat stores), ensures fetal nutrition |
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Term
| progesterone during pregnancy |
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Definition
| essential hormone for pregnancy maintenance, placenta produces it by around 8 weeks, rises throughout pregnancy, maternal LDL cholesterol is substrate (trophoblast cells have receptors for LDL), prevents uterine contractions, inhibits prostaglandin formation, inhibits T-cell immune response to pregnant uterus |
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Term
| estrogen during pregnancy |
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Definition
| estradiol and estriol are major hormones produced, rise throughout pregnancy, production requires fetoplacental unit, involved in implantation, increases uterine size and blood flow, assists fetal organ development |
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Term
| estrogen effect on pregnant woman |
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Definition
| increases breast and adipose tissue, causes peripheral vasodilation (sinus congestion/bleeding gums/sensation of warmth), increases blood volume/heart rate/cardiac output/uterine blood flow |
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Term
| progesterone effect on pregnant woman |
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Definition
| allows smooth muscle relaxation (increased GERD and constipation), decreases contractions, increases minute ventilation |
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Term
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Definition
| birth process, has hormonal/mechanical/maternal/fetal factors involved, estrogen activates events while progesterone inhibits it, paracrine factors may be most important |
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Term
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Definition
| sharp decrease in progesterone prior to labor, amniotic fluid prostaglandin concentration increases at onset (stimulates contractions and cervical ripening), oxytocin augments labor by increasing uterine responsiveness, fetal cortisol rises, vaginal/cervical dilation cause explosive pulsatile oxytocin release ("Fergusson reflex") |
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Term
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Definition
| occurs in 3% of live births, approximately 2/3rds are fraternal, division of zygote at day 13 causes conjoining, incidence of dizygotics affected by: assisted reproduction, ethnicity, maternal age and other characteristics |
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Term
| contraception by preventing germ cell contact |
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Definition
| includes coitus interruptus, rhythm method, barrier methods (condoms, etc.) |
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Term
| contraception by preventing ovulation |
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Definition
| inhibition of LH and FSH through negative feedback, also adversely affects environment of reproductive tract, includes emergency methods w/ high doses of progestin, IUDs, etc. |
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Term
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Definition
| production of milk, controlled primarily by pituitary hormones, requires suckling to continue, major source of nutrition for newborns |
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