Reproductive Sys

hrdcorhrvivor's version from 2017-05-13 07:14

Section 1

Question Answer
meiosisdivision of cell that results in 4 haploid daughter cells, only in gametes
meiosis 1homologous chromosomes for tetrad via synapsis, crossing over occurs, homologues are separated, 2 haploid daughter cells
meiosis 2 sister chromatids are separated, 4 haploid daughter cells
testes200-300 lobules with 1-3 seminiferous tubules, surrounded by scrotum used to regulate temp
testes functionproduce sperm within seminiferous tubules, secrete testosterone from leydig cells
sertoli cellsform continous layer around each tubule, forms blood testis barrier, support protect and nourish developing sperm, regulate production
sertoli cells secreteandrogen binding protein ABP, binds to testosterone and concentrates it in tubules to stimulate spermatogenesis, inhibin which inhibits secretion of FSH
leydig cellsbetween seminiferous tubules, produce testosterone, begin secretion at puberty
hypothalamic-pituitary-gonadal axisused to regulate spermatogenesis and oogenesis
GnRHstimulated release of FSH and LH
FSHstimulates sperm production in males and ovarian follicle development in females
LHinduces ovulation and formation of corpus luteum (which secretes estrogen and progesterone in females) stimulates leydig cells to release androgens like testosterone
inhibinreleased by sertoli cells in males and granulosa cells in females, inhibits FSH
slow pulses of GnRHfavor FSH
faster pulses of GnRHfavor LH
spermatogenesis65-75 days, spermatogonia: diploid stem cells, undergo mitosis (half replace themselves, half continue) primary spermatocyte: diploid, undergo meiosis 1 (form 2 secondary spermatocytes) secondary spermatocyte: result of meiosis 1, haploid (undergo meiosis 2, 4 spermatids) spermatids: attached to eachother
spermiogenesisspermatids turn into sperm, acrosome and tail form
spermhead: haploid nucleus, acrosome filled with enzymes used to penetrate follicle. midpiece: mitochondria. tail: flagellum that propels sperm
male reproductive ductssperm exit the seminiferous tubules and enter epididymis to mature, reabsorbed if not ejaculated, ductus deferens conveys sperm toward ejaculatory duct
erection reflexthoughts/stimulation activate PSNS, bulbourethral glands secrete mucus for lubrication, nitric oxide for sm in penile arterioles to relax. veins compress
viagraprevents cyclic gmp breakdown so erections last longer
ejaculation emission phaseSNS, contraction of sm in ducts, emptying of sperm and accessory gland secretions into urethra: semen
ejaculation expulsion phasemotor neuron induced contraction of skeletal muscle at base of penis, forceful expulsion of semen

Section 2

Question Answer
ovariesproduction of gametes ova through oogenesis, estrogen, progesterone, relaxin, inhibin.
ova at birth1-2 million primary oocytes arrested in meiosis 1
ova at pubertyestimated between 100-300,000
oogenesis defbegins at birth, accelerates at puberty, ends at menopause, occurs monthly as hormone cycle goes up and down
oogoniadiploid stem cells give rise to primary oocytes
primary oocytesbegin meiosis, arrest in prophase 1, occurs during fetal development, maintain arrested state until puberty, one primary oocyte and one follicle with mature during each menstrual cycle
secondary oocytesformed after chosen primary follicle completes meiosis 1, 1st polar body formed is discarded genetic material and little cytoplasm, begins meiosis 2 but arrests in metaphase 2
primordial folliclecontains primary oocyte surrounded by one layer of follicular cells
primary follicleprimary oocyte enlarges, follicular cells divide forming mult layers, now called granulosa cells
secondary folliclegranulosa cells secrete fluid to form antrum, zona pellucida found between primary and granulosa cells, barrier sperm must penetrate, secrete estrogen and inhibin, theca interna secrete testosterone which granulosa cells turn to estrogen
graafian (mature) folliclelarge fluid filled antrum, secondary oocyte ready for ovulation
corpus luteumremnants of follicle after ovulation, secrete estrogens and progesterone, maintain uterine environment
corpus albicansif no fertilization occurs, corpus luteum regress to this stage, does not secrete hormones
phases of the female cycle24-35 days average being 28 days, caused by cyclical changes in hormones, ovarian cycle and uterine cycle occur simultaneously