lecture 20 - reproductive system Flashcards
female gonads
ovaries
ovaries
pari fo almond sized organs
ovaries function
produce gametes and hormones
oogenesis results in
formation of a single haploid secondary oocyte
ovarian follicles consist of
oocytes in various stages
supporting cells
- follicular cells or granulosa cells based on stage
- these provide nourishemtn to the follicle
atresia
process where underdeveloped germ cells degenerate
follicular histology (layers)
zona pellucida
corona radiata
antrum
theca folliculi
sequence of changes in follicles
primordial
primary
secondary
tertiary (mature)
corpus luteum
corpus albicans
zona pellucida
clear glycoprotein layer between oocyte and granulosa cells
theca folliculi (2)
outermost layer of cells on the basement membrane of a follicle
theca interna
- internal layer of secretory cells that secrete androgens
theca externa
- outer layer of stromal cells
antrum
formed by granulosa cells secreting follicular fluid
corona radiata
inner layer of granulosa cells that is attached to the zona pellucida
this layer is still attached to oocyte at ovulation
whole oogenesis process
- oogonium under goes mitosis
- forms primary oocyte
- undergoes meiosis 1 to form secondary oocyte and first polar body
- undergoes meiosis 2, must be fertilized to complete meiosis 2, and forms ovum and second polar body
- nuclei of sperm and ovum form zygote (2n)
germ cells from umbilical vessicle do waht
migrate to ovary and become oogonia in early life
what stage does oogenesis stop at
primary oocytes stop in prophase 1 until puberty
oocyte amounts
200k-2mil at birth
40k remain at puberty
only about 400 mature in a womans life
all of the others degenerate (atresia0
what causes oogenesis to resume from prophase 1
each month, hormones cause meiosis 1 to resume in several follicles so that meiosis 2 is started just before ovulation
note: only one follicle reached tertiary follicle stage each month
:)
where does the secondary oocyte stall
metaphase of meiosis 2 under fertilization
what causes meiosis 2 in secondary oocytes to resume
fertilzation by sperm
forms a zygote
what causes maturation of follicles
FSH and LH monthly
when is meiosis 1 completed
before ovulation in the tertiary (mature) follicle
when does meiosis 2 begin
right before ovulation
uterine tubes function
transport secondary oocyte/ovum/zygote form ovaries to uterus
site of fertilization
fimbriae + function
fingerlike projections of uterine tube that sweep ovum into uterine tubes
epithelium of the uterine tubes contains (2) waht do they do/
cilia
- move ovum along
- works with peristalsis
peg cells
- secrete fluid to nourish ovum
fertilization usually occurs: and where
within 24 hours of ovulation in ampullae of uterine tubes
when does a fertilized zygote reach uterus
about 7 days after ovulation
uterus functions (5)
- transport sperm
- menstruation
- implantation
- development of fetus
- labour
parts of uterus and what they are
fundus - top portion of muscle
body- main portion of muscle
cervix - gateway in
interior uterine cavity - inner space
cervical canal - just past cervix
secretory cells in mucosa of cervix secrete
cervical mucus
uterus histology (3)
inner endometrium
middle myometrium
outer perimetrium (serosa)
inner endometrium layers (3) and what they do
compact layer (sheds)
functional layer (sheds)
basal layer (stem cells give rise to new compact and functional layers after shed)
middle myometrium layers and function
3 smooth muscle layers
contract under influence of oxytocin during labour
outer perimetrium layers and function
simple sq epi and areolar CT
part of peritoneum
ectopic pregnancy (extrauterine)
2% of all pregs
often misdiagnosed
abdominal implantation
fibromuscular layer of vagina is lined with
mucous membranes
muscular layers of vagina
outer longitudinal and inner circular
mucosa of vaginal contains
normal flora nad organic acids
continuous with uterus
functions of vagina (3)
passageway for menstrual flow
recieve sperm
form lowr birth canal
vulva parts (7)
external urethra orifice
mons pubis
labia majora
labia minora
clitoris
vaginal orifice
hymen
functions of vulva (3)
protection
sensory tissues
micturition
mammary glands are modified what?
modified sudoriferous glands that produce milk
mammary glands breakdown
20 lobes that have lobules
alveoli
tubules
ducts
sinuses
mammary alveoli
glandular cells that secrete milk into ducts
lactiferous ducts
open in the nipple to eject milk
lactatioj
production and release of milk
maternal milk contains (2)
anitbodies and immune cells that will protect the infant during early life
prolactin
increases during pregnancy
inhibited by progesterone until delivery
lactation reflex
suckling activate stretch receptors
- sends NP to hypothalamus
- stops PIH
- stimulates PRH
- stimulates production of prolactin
milk ejection reflex
oxytocin cause release of milk into mammary ducts
- oxytocin triggered by nipple touch receptors, babys cry, genital touch
oxytocin causes contraction of myoepithelium around alveoli
milk moves from alveoli into mammary ducts
female reproductive cycles
ovarian and uterine cycles
ovarian cycle
series of events in the ovaries during and after the maturation of the oocyte
uterine cycle
series of changes of the endometrium to prepare for the arrival of an ovum
what regulates the ovarian cycle
hormones from the anterior pituitary like LH and FSH
waht regulates the uterine cycle
hormones from the ovaries like porgesterone and estrogen
what controls the entire female reproductive cycle
GnRH from hypothalamus
gonadotropin releasing hormone
- stimulates LH and FSH, which stimulates pathways that end in production of estrogen and progesterone
FSH role in female reprod cycle
stimulate initial growth of follicles, that in turn secrete estrogen
what maintains reproductive organ function
estrogen
LH role in female reprod cycle
stimulate ovulation and promotes formation of corpus luteum, which in turn secretes est, progest, realxin, and inhibin
estrogen functions (4)
- promote develoment and maintenance of female reprod structures
- increase protein anabolism
- lower blood cholesterol
- after menstruation stimulated regrowth of endometrial layers (functional layer)
what inhibits teh release of GnRH
moderate estrogen/progesterone levels in blood
this in turn inhibits FSH and LH
progesterone function
works with estrogen to prepare endometrium for implantation and mammary glands for milk synthesis
relaxin functions
relax the uterus which inhibits contractions to make implantation easier
relaxes pubic symphysis during pregnancy and dilates cervix to facilitate labour
inhibin
inhibits secretion of FSH, and LH to a lesser extent
phases of female reprod cycel
menstruation
preov
ov
post ov
uterine cycle phases
menstrual phase
proliferative
secretory
menstruation phase (in ovaries and in uterus)
1-5
in ovaries
- primordial follicles begin to develop into primary and secondary due to FSH
in uterus
- function and compact layer of endometrium are shed, discharging 50-150ml of blood, tissue, mucus, and epi cells
why does discharge of endometrium occur
because estrogen and progest levels fall, and prostaglandins release which constricts uterine arterioles
this starves cells of O2 and they die`
hormones during menstruation
all relatively low, FSH highest
preov phase (in ovaries and in uterus)
6-13
in ovaries (follicular phase)
- primary folicles develop into secondary
- dominant follicel continues to increase estrogen prod and becomes tertiary follicle
- other less developed follicles degen
in uterus (proliferative phase)
- increasing estrogen levels repair and thicken functional and compact layers of endometrium
hormones in pre ov phase
estrogen high, LH higher (surge)
progest low, FSH small jump
ovulation phase
14
- high levels of estrogen during last part of preov phase exert positive feedback on GnRH and LH to cause LH surge
- LH surge causes rupture in follicle and expulsion of secondary oocyte into pelvic cavity
- oocyte is swept into tube by fimbriae
no uterine cycle equivelant
ovulation hromones
LH surge has gone down a bit but still the highest, est is lower, FSH lower
progesterone is on the rise
after ovulation:
tertiary follicle collapses
- LH stimulates follicular cells to form corpus luteum
- LH stimulates Corpus luteum to secrete its hormones (all 4)
post ov phase (in ovaries and in uterus)
15-28
in ovaries (luteal phase)
- both est and progest are large in quantity (vai corpus luteum)
- if oocye is not fertilized, corpus luteum becomes corpus albicans (hormones drop, GnRH,LH,FSH rise), new ovarian cycle begins
- if oocyte IS fertilized, embryo secrete human chorionic gonadotropin which maintains corpus luteum and its job
in uterus (secretory phase)
- hormones from corpus luteum promote thickening of endometrium
- more vascular and more glands
- endometrial glands secrete glycogen
- if no fertilization, menstrual phase begins as corpus luteum degenerates
post ov hormones
progest highest but falling, all others fairly low
recap of ovarian cycle (3)
follicular (preov) phase
- day 1- ov
- overlaps with menstrual phase of uterine
- release FSH - stimulate follicles
- follicles secrete estrogen
ov phase
- day 14
- high estrogen = LH/GnRH release from gonadotrophs and hypothal respectively
- release of secondary oocyte from ruptured follicle
- pregnancy can occur
luteal (postov) phase
- formation of corpus luteum
- est + progest release
- if pregnant, corpus luteum of pregnancy forms, if not pregnant corpus of menstruation forms and degens
uterine cycle recap (4)
menstrual phase
- no fert of egg
- est /progest drop
- corpus luteum degens
- shedding of endometrium
regenerative phase
- 4-6
- regen of basal layer of endometrium
proliferative phase
- 7-15
- corresponds to follicular phase of ovarian
- est from follicular phase stimulates this phase
- proliferation of endometrium
secretory phase
- 16-28
- corresponds to luteual phase of ovarian
- controlled by progesterone from corpus
- endometrium us fully developed
hormonal birth control
typically a combo of est/progesterone
negative feedback on ant pituitary / hypothal to prevent FSH and LH secretion
causes no follicular development
tubal ligation
like a vasectomy but females
