pregnancy Flashcards
(29 cards)
Fertilization: male
sperm capacitation:
- enhance motility
- membrane fragile: release hydrolytic enzyme in acrosome
- only capacitated sperm can move towards ovum
Fertilization: progress
1.) corona radia and zona pellucia surround the ovulated oocyte: sperm d hyaluronidase enzyme digest conrona radia d granulosa cell
2.) acrosomal reaction
3.) binding
4.) fusion
5.) blocks to polyspermy
fertilization: acrosomal reaction
1.) sperm binds to receptors in the zona pellucia -> increase Ca level -> trigger release of acrosomal enzyme -> many sperm geh acrosomal enzyme digest a bole in zona pellucia
Fertilization: binding
sperm’s membrane binds to the oocyte’s sperm-binding receptor -> fusion
Fertilization: fusion
sperm and oocyte plasma membrane fuse: sperm content enter the oocyte
Fertilization: block polyspermy
oocyte membrane block
-> sperm-binding receptor are shed
cortical reaction: Ca lv increase triggers exocytosis of cortical granules -> harden zona pellucia and destroy sperm-binding receptor
pronuclei
sperm and ovum nuclei swell
-> pronuclei approach each other and a mitotic spindle form between them
–> chromosome intermixed
—> END OF FERTILIZATION
ZYCOTES formed
cleavage
produce small cells: enhance nutrient uptakes
trophoblast
- protect the conceptus from the immunosuppressive effect (attack) from mother
- secrete digestive enzyme and growth factor onto the endometrial surface (thicken)
proliferate and form cytotrophoblast and syncytiotrophoblast (HCG)
before implantation: blastocytes
blastocytes floats in the uterine cavity: nourished by the glycoprotein-rich uterine secretion
Implantation: mucosa prepared
integrin and selectin proteins in trophoblast bind to the extracellular matrix and to selectin-binding carbohydrate on the inner uterine wall
Implantation: mucosa not prepared
blastocytes detaches and floats to a lower level
-> implant when find a site with proper receptors
HCG
maintain corpus luteum -> secrete progesterone and estrogen
placenta
chorionic villi: contain rich network of capillaries
umbilical cord
Placenta: function
1.) exchange of substances
2.) production of hormones
- progesterone and estrogen
- human placental lactogen: lower the usage of maternal glucose: more availability of maternal glucuse; mobilize fat from maternal adipose tissue: more free fatty acid levels
- relaxin: relaxation of ligament in pubic symphysis
function of estrogen
- enlargement of uterus
- relaxation and softening of pelvic ligaments and pubis symphysis
- ductal development of mammary gland
- secretion of prolactin
function of progesterone
- maintenance of the endometrium
- decrease the contractility -> prevent abortion
- increase secretion of mother fallopian tubes -> provide appropriate nutritive matter
- help estrogen -> prepare lactation
labour: initiation
estrogen highest level:
- stimulate myometrial cell to form abundant oxytoxin receptor
- irregular uterine contraction
oxytoxin: uterus contract, stimulate placenta to prostaglandins
prostaglandins: more contraction
(positive feedback)
labour: dilation
amnion ruptures-> releasing amniotic fluid
labour: explusion stage
strong contraction
labour: afterbirth
strong contraction: compress uterine blood vessel-> linit bleeding
all placental fragment should be removed: prevent bleeding
milk production: estrogen
development of ductal system
inhibit milk production during pregnancy
milk production: progesterone
development of lobule-alveolar system
inhibit milk production during pregnancy
milk production: prolactin
development of lobule-alveolar system;
milk production
