Reproductive system Flashcards
chromosomes
long strands of DNA and genetic material
wrapped in histones
diploid
46 chromosomes (half from xx other xy
-referred as 2n
haploid
23 chromosomes
n
gametes
haploid cells made in gonads
germ line cells
cells that give rise to gametes through meiosis
oocytes
eggs
contain X chromosome
sperm
contains x or y chromosome
determines sex
meiosis
diploid cells become haploid gamete
interphase (replicates DNA)
prophase, metaphase, anaphase, telophase and cytokinesis 1
prophase, metaphase, anaphase, telophase and cytokinesis 2
external genitalia in males
penis and scrotum (has testes)
order of fluid release during ejaculation
bulbourethral gland, seminal vesicle, prostate
testes
produce sperm
produce testosterone and inhibin in response to GnRH from anterior pituitary
epididymis
site of sperm maturation and storage
vas deferens
tube connecting testes to ureter
seminal vesicle
contributes fluid to semen during ejaculation
-fluid is rich in fructose and enzymes
prostate
gland secretes enzymes and fluid to help neutralise acidic environment of urethra and vagina
-without it, sperm would die due to acidity
-regulates by testosterone
ejaculatory duct
drains into urethra
bulbourethral gland
release alkaline and lubricating fluid
urethra in males
has urine and sperm
penis
consists of erectile tissue
seminiferous tubule
site of spermatogenesis, where meiosis occurs
3 cells spermatocytes, Sertoli cells, Leydig cells
spermatocytes
adult stem cells that are developing
sertoli cell
support and regulate spermatogenesis
-creates blood teste barrier
FSH receptors
-produces inhibin
Leydig cells
produce testosterone
-located between seminiferous tubules
LH receptors
spermatogenesis
production of sperm, results in haploid cells
spermatogenesis steps
- spermatogonia/ germ cell (2n/46c) at outer edge of somniferous tubule
- spermatogonia divide by mitosis into 2 cells 1 spermatogonia (2n) and 1 primary spermatocyte (2n)
- primary spermatocyte crosses the tight junctions and more internal divide by meiosis into 2 secondary spermatocytes each n
- secondary spermatocytes moves more internal and divided by meiosis 2 in 4 spermatids, each n/23c
spermatozoa
released by sertoli cells into lumen seminiferous tubules
-mature spermatids
-sperm
-shed cytosol and grow tail
-mature in the epididymis
spermatozoa’s tail
allows sperm to propel itself towards an oocytes
spermatozoa’s mitochondrial spiral
densely packed to generate NRG to support tail movement
spermatozoa’s head
nucleus with 23 c/n
spermatozoa’s acrosome
contains enzymes and allows sperm to penetrate oocyte
spermiogenesis
-spermatids > sperm/ spermatoza
takes 64-72 days
HPG for males
hypothalamus (GnRH) > ant. pit. (FSH and LH)>
-sertoli cells (FSH stims. spermatogenesis and production of inhibin)
-leydig cells (LH sti. production of testosterone)
-inhibin - feedback on ant. pit.
-testosterone - feedback on hypothalamus and ant. pit.
testosterone
muscle growth
produced from cholesterol
fimbrea
capture the oocyte after it is released by ovary
-finger projection that sweeps oocyte in uterine tube
ovary
site of developing female gamete
-response to FSH + LH, secretes estrogen + progesterone
-releases oocyte during ovulation
uterus
muscular organ
-site of embryo implantation into endometrium
-development is regulated by estrogen, maturation by progesterone
cervix
forms between vaginal canal + uterus
-secretes mucus
-high estrogen, thinner cervical mucus, high progesterone thicker mucus
uterine tube
-where sperm + oocyte meet + fertilization
-has cilia moving oocyte or embryo to uterus
-movement regulated by progesterone
what stage blocks most oocyte
oocytes begin meiosis then stop at prophase/diplotene stage
polar body
halpoid cell that can’t be fertilized
-with unneeded chromosomes + cytoplasm
made during metaphase 2
syngamy
joining sperm + oocyte DNA
oogenesis
oocyte development
-formation of zona pellucida (egg shell)
granulosa + theca cells
contribute to maturation, maintenance + care
-secretes estrogen and progesterone
-together + oocyte make up follicle + matures through folliculogenesis
folliculogenesis
process where ovarian follicles mature, small primordial follicles to larger preovulatory follicles
-leads to ovulation or atresia
ovulation vs. atresia
-release of oocytes
-follicle degenerates
stages of folliculogenesis
primordial follicle
primary follicle
secondary follicle
tertiary/antral follicle
preovulatory follicle
primordial follicle
initial stage
-has oocyte with single layer of granulosa cell
primary follicle
activates 30-50 primordial follicle
-1 will ovulate, the rest atresia
-multi layers of granulosa cells
-zona pellucide forms
secondary follicle
-granulosa cells multiple
-theca cells form around follicle
tertiary/antral follicle
forms antrum (fluid filled cavity)
-granulosa and theca cells multiples
-follicle grows larger
preovulatory follicle
follicle matures + ready for ovulation
-antrum enlarges
corpus luteum
remnants of follicles form it
-secretes progesterone for potential pregnancy
-no, pregnancy, degrades into scar tissue called corpus albican
what system regulates female reproductive system
hypothalamic-pituitary-gonadal
2 processes
folliculogenesis and endometrial changes
endometrial changes
thickening and prep of uterine lining for potential implantation
no pregnancy
corpus luteum breaks down and endometrial lining sheds
cycle restarts
not * post ovulation both G and T cells convert to corpus luteum cells and express LH receptors
uterine lining
estrogen stimulates thickening of lining during 1st
-after ovulation, progesterone stabilizes lining, if not fertilized, there is a drop in progesterone and sheds the lining
birth control
-synthetic estrogen + progestin to suppress ovulation
-constant estrogen + progestin, negative feedback to hypothalamus + pituitary to stop LH surging
-progesterone prevents estrogen from being carcinogenic
menopause
low reproductive hormones by non responsive ovaries
-45-55years
-stops ovulations ad periods
why do hormones change during menopause
ovaries less response
-ovarian follicle depletion (few follicles, lost through ovulation and atresia)
-less est.(produced by developing follicles) + prog. produced (produced by corpus luteum)
-increase FSH and LH, b/c less negative feedback
menopause effects
hot flashes + night sweats
-irregular and absent periods
-bone loss
-mood changes
-vaginal dryness
oocyte’s pathway
ovary> fimbrea>uterine tube>uterus
oogenesis
oogonia/stem cell (in utero > primary oocyte (can be in utero, pre and post puberty) > secondary oocyte (post puberty) > zygote (post puberty)
-interphase: oogonia
-primary oocyte stops in prophase 1 until puberty
meiosis 1 is completed with secondary oocyte and polar body
-secondary oocyte stops in metaphase 2 until its fertilized or degraded if not fertilized
-if fertilized, meiosis 2 is completed producing a zygote and polar body
