Physiology of pregnancy, parturition, and lactation Flashcards
what does estrogen cause the cervix to do
produce a watery mucus which forms channels to aid passage of sperm through cervix
-also causes contractions of myometrium to help propel sperm up toward oviduct
what does estrogen cause the cervix to do
produce a watery mucus which forms channels to aid passage of sperm through cervix
-also causes contractions of myometrium to help propel sperm up toward oviduct
in vivo sperm must breach 3 barriers during the process of fertilization
1) expanded cumulu
2) zona pellucida
3) plasma membrane of the egg (oolemma)
as the male pronuclei and female pronuclei are pulled together what do they do
they replicate their DNA
what day does fertilization usually occur
day 15 or 16 of the menstrual cycle
how does the cavity inside the morula form
active transport of Na+ into morula and osmosis of water = blastocyst
before the embryo implants in the endometrium where does the embryo get its nutrients
from uterine secretions
the presence and action of ___ may determine extent of implantation window and what are they
what enhances
what inhibits
pinopods
- enhanced by progesterone inhibited by estrogens
- endocytose macromolecules and uterine fluid in lumen of uterus
- may allow embryo and uterine epithelium to approximate one another more closely
how does blastocyst avoid rejection by maternal cellular immune system
- release immunosuppressive agents
- releases hCG which is an immunosuppressant and sustains CL
the ___ of the blastocyst secrete ___ that digest the outer-lying zona pellucida
trophoblasts
proteases
-the blastocyst now has “hatched” and can attach to uterine wall
which layer of trophoblast is rapidly proliferating
cytotrophoblast
in vivo sperm must breach 3 barriers during the process of fertilization
1) expanded cumulu
2) zona pellucida
3) plasma membrane of the egg (oolemma)
as the male pronuclei and female pronuclei are pulled together what do they do
they replicate their DNA
what day does fertilization usually occur
day 15 or 16 of the menstrual cycle
how does the cavity inside the morula form
active transport of Na+ into morula and osmosis of water = blastocyst
before the embryo implants in the endometrium where does the embryo get its nutrients
from uterine secretions
the presence and action of ___ may determine extent of implantation window and what are they
what enhances
what inhibits
pinopods
- enhanced by progesterone inhibited by estrogens
- endocytose macromolecules and uterine fluid in lumen of uterus
- may allow embryo and uterine epithelium to approximate one another more closely
how does blastocyst avoid rejection by maternal cellular immune system
- release immunosuppressive agents
- releases hCG which is an immunosuppressant and sustains CL
the ___ of the blastocyst secrete ___ that digest the outer-lying zona pellucida
trophoblasts
proteases
-the blastocyst now has “hatched” and can attach to uterine wall
which layer of trophoblast is rapidly proliferating
cytotrophoblast
syncytiotrophoblast adhesive, invasive and endocrine functions
adhesive: has cadherins and integrins that bind uterine surface epithelia
- invasive: secrete mettaloproteases and hydrolytic enzymes
- endocrine: secrete hCG and progesterone
how does hatching occur
blastocyst secrete factor that converts plasminogen from the uterine cavity to plasmin which is a lytic factor that can break down ZP
what is the first stage in implantation
what protein involved
apposition: earliest contact between blastocyst wall, trophoectoderm and endometrial epithelium
- MUC1 might be involved in apposition, a transmembrane glycoprotein at apiclal surface of endometrial epithelial cells during windown of implantation
what is the second stage of implantation
adhesion: tropoblast attach to uterine epithelium through microvilli of trophoblast
- integrin ligand receptor interactions
- this may dislodge decidual cells from connection to underlying basal lamina, which enables blastocyst to perform invasion
last stage of implantation
invasion: blastocyst attaches to endometrial epithelium, trophoblastic cells rapidly proliferate and diff into inner cytotroph and outer syncytio
- protrusions from syncytiotrohp extend among uterine epithelial cells
- secrete TNF-a which interferes with cadherins and B-catenin
- secrete hCG which is autocrine growth factor for blastocyst
- secrete metalloproteases and serine proteases to degrade ECM
site of penetration of syncytiotroph
uterine stromal cells become polyhedral and full of lipids and glycogen (decidual cells)
- blastocyst superficially implants in zona compacta
- syncyt invade blood supply of mom
the mature placenta is composed of what 3 major structures
chorionic villi, intervillous space, and decidua basalis
___ arteries from the mother empty into ___ which drained by maternal veins
spiral, intervillous space
fetal blood flow
umbilical arteries carry deoxygenated blood away from fetus
-single umbilical vein brings O2 and nutrients to fetus
2 functions of amniotic fluid
mechanical buffer protecting fetus from external insults
-fetus excretes waste products through here
how does fetus not suffer from lack of decreased O2 coming in
fetal Hb has higher affinity for O2
- more hemoglobin
- bohr effect
- high cardiac output of fetus
what goes from fetus to maternal circulation
Water, Urea and waste, CO2, hormones
what goes from mother circulation to fetus
No Homo VIDEO
nutrients hormones, viruses, IgG, drugs, electrolytes (h20), O2
hCG and progesterone
maintains high level of luteal derived progesterone production during first 10 weeks of gestation
what causes morning sickiness
rapid increase in hCG
function of hPL
produced in syncytiotrohoblast
- antagonistic action to insulin
- increases glucose availability
- increases lipolytic actions to help mother shift to use of free fatty acids for energy
what enzmes do syncytiotrophoblast express in high levels
also what receptors
- desmolase
- 3B-HSD
- lack 17-a hydroxylase and 17,20 lyase
- also have LDL receptors
