Early Nutrition and Lifestyle Factors
Item
Title
Early Nutrition and Lifestyle Factors
Description
The placenta is literally the “tree of life.” The derivation of the word
placenta comes from Latin for cake (placenta), from Greek for flat, slab-like
(plako´enta/plakou´nta), and from German for mother cake (mutterkuchen), all
referring to the round, flat appearance of the human placenta. Structurally, the
placenta is a hemochorial villous organ. The placenta is the highly specialized
organ of pregnancy that supports the normal growth and development of the fetus.
Growth and function of the placenta are precisely regulated and coordinated
to ensure that the exchange of nutrients and waste products between the maternal
and fetal circulatory systems operates at maximal efficiency. After implantation,
trophoblast cells proliferate and differentiate along two pathways described as
villous and extravillous trophoblast cells. Non-migratory, villous cytotrophoblast
cells fuse to form the multinucleated syncytiotrophoblast, which forms the outer
epithelial layer of the chorionic villi. It is at the terminal branches of the chorionic
villi that the majority of fetal/maternal exchange occurs. Extravillous trophoblast
(EVT) cells migrate into the decidua and remodel uterine arteries. This facilitates
blood flow to the placenta via dilated, compliant vessels, unresponsive to maternal
vasomotor control. However, all these tasks depend on normal vascular development within the placenta itself. Placentation begins with the implantation of
the blastocyst; the outermost cells of the blastocyst give rise to the trophoblast,
a specialized epithelium that during implantation invades the decidua and the
inner myometrium, developing the placenta. The cell columns are formed
by a subpopulation of cytotrophoblast cells called extravillous trophoblast
that proliferates, invades the decidua and superficial layer of myometrium, and
transforms the spiral arteries (a terminal branch of the uterine arteries that reach
the endometrial surface). Complete transformation of spiral arteries is required
for a successful pregnancy since the transformed spiral arteries become low resistance vessels allowing a normal blood flow to the feto-placental unit.
placenta comes from Latin for cake (placenta), from Greek for flat, slab-like
(plako´enta/plakou´nta), and from German for mother cake (mutterkuchen), all
referring to the round, flat appearance of the human placenta. Structurally, the
placenta is a hemochorial villous organ. The placenta is the highly specialized
organ of pregnancy that supports the normal growth and development of the fetus.
Growth and function of the placenta are precisely regulated and coordinated
to ensure that the exchange of nutrients and waste products between the maternal
and fetal circulatory systems operates at maximal efficiency. After implantation,
trophoblast cells proliferate and differentiate along two pathways described as
villous and extravillous trophoblast cells. Non-migratory, villous cytotrophoblast
cells fuse to form the multinucleated syncytiotrophoblast, which forms the outer
epithelial layer of the chorionic villi. It is at the terminal branches of the chorionic
villi that the majority of fetal/maternal exchange occurs. Extravillous trophoblast
(EVT) cells migrate into the decidua and remodel uterine arteries. This facilitates
blood flow to the placenta via dilated, compliant vessels, unresponsive to maternal
vasomotor control. However, all these tasks depend on normal vascular development within the placenta itself. Placentation begins with the implantation of
the blastocyst; the outermost cells of the blastocyst give rise to the trophoblast,
a specialized epithelium that during implantation invades the decidua and the
inner myometrium, developing the placenta. The cell columns are formed
by a subpopulation of cytotrophoblast cells called extravillous trophoblast
that proliferates, invades the decidua and superficial layer of myometrium, and
transforms the spiral arteries (a terminal branch of the uterine arteries that reach
the endometrial surface). Complete transformation of spiral arteries is required
for a successful pregnancy since the transformed spiral arteries become low resistance vessels allowing a normal blood flow to the feto-placental unit.