Search results
Results from the WOW.Com Content Network
The placenta (pl.: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation.It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate maternal and fetal circulations, and is an important endocrine organ, producing hormones that regulate both maternal and fetal ...
Anatomy scan image of a human placenta and umbilical cord (colour Doppler rendering) showing central placement of the cord in the placenta and three vessels in the cord, which is the normal physiology. A standard anatomy scan typically includes: [4] Fetal number, including number of amnionic sacs and chorionic sacs for multiple gestations
Placenta can also be divided according to what kind of structure it develops from. There are two vessel-rich features in the amniote, the yolk sac and the allantois. When the chorion fuses with the former, the result is a choriovitelline placenta. When it fuses with the latter, the result is a chorioallantoic placenta.
A change in the composition of the microbiota in the placenta is associated with excess gestational weight gain, and pre-term birth. [10] The placental microbiota varies between low birth weight infants and those infants with normal birth weights. [ 13 ]
The form of the human placenta is generally classified as a discoid placenta. Within this, the cotyledons are the approximately 15-25 separations of the decidua basalis of the placenta, separated by placental septa. [3] Each cotyledon consists of a main stem of a chorionic villus as well as its branches and sub-branches. [3]
The placenta later develops to nourish the embryo, which grows through embryonic and fetal development until childbirth. During this process, the uterus grows to accommodate the growing fetus. [23] When normal labor begins, the uterus forcefully contracts as the cervix dilates, which results in delivery of the infant. [23]
Velamentous Placenta: Normal umbilical cord insertion and velamentous umbilical cord insertion in pregnancy, with and without vasa previa. Specialty: Obstetrics Symptoms: Blood vessel compression, [1] [2] decrease in blood supply to the fetus, [2] [3] impaired growth and development of the fetus. [4] [5] Risk factors
In obstetrics, a cephalic presentation or head presentation or head-first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation, where the occiput is the leading part (the part that first enters the birth canal). [1]