Flashcards in Female Repro III Deck (23):
how much of the surface of the fetal/maternal barrier is just amnion and how much is placenta?
3/4 amnion, 1/4 placenta
fetal cells contribute what two layers? maternal layer?
amnion and chorion are fetal (extraembryonic tissues); decidua is maternal
properties of the amnion
very thin, cuboidal or columnar epithelium and underlying mesenchyme; high tensile strength
is the amnion vascularized?
chorionic tissues are made up of what type of cell?
what is the name of the fetal layer that contacts the placenta? what type of trophoblast cells make it up?
chorion laeve; cytotrophoblasts
what are the properties of the chorion laeve?
thin, avascular, mesenchymal layer touches amnion mesenchyme; cytotrophoblastic layer contacts the decidua
name four gross functions of the placenta
metabolic, endocrine, exchange and antibodies
exchange functions in depth?
uptake of nutrients, removal of waste products, exchange of gases
metabolic functions in depth?
cholesterol, amino acids, fatty acids can be produced in the placenta
synctiotrophoblast can produce estrogen
what is the concept of placental function?
to bring the fetus and maternal circulations into close proximity without actually anastomosing
250-500 ml of blood; 2 cm tall, 20 cm long, ovoid, 500g
the lobules on the placenta are called
what's the name of the connective tissue in which the chorionic vessels run?
what is Wharton's Jelly made of?
hyaluronic acid and chondriotin sulfate
what are the three types of villi in the placenta?
stem, terminal and anchoring
what mechanisms are used for importation of material into the trophoblast?
passive and facilitated diffusion; active transport and receptor mediated endocytosis
what do the cytotrophoblasts do to the spiral artery circulation?
make them impervious to peptides that would constrict the blood vessels (this may lead to hypertension)
what enters the trophoblast by diffusion?
gases and vitamins; alcohol/drugs of abuse/therapeutic drugs
what enters the trophoblast by transporters?
sugars, amino acids and calcium; drugs of abuse/therapeutic drugs can interfere with transporters
what enters the trophoblast by endocytosis?
tranferrin and antibodies; autoantibodies (if present) and RBC antibodies (can be a problem if fetus is different from mother)