Search results
Results from the WOW.Com Content Network
Human embryology is the study of this development during the first eight weeks after fertilization. The normal period of gestation (pregnancy) is about nine months or 40 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus .
This constitutes the so-called capsule of the space. Each lacuna is generally occupied by a single cell, but during the division of the cells, it may contain two, four, or eight cells. Lacunae are found between narrow sheets of calcified matrix that are known as lamellae (/ l ə ˈ m ɛ l i / lə-MEL-ee).
Placenta with attached fetal membranes (ruptured at the margin at the left in the image), which consists of the chorion (outer layer) and amnion (inner layer).. The part of the chorion that is in contact with the decidua capsularis undergoes atrophy, so that by the fourth month scarcely a trace of the villi is left.
B.—Diagram of the female type of sexual organs. C. Greater vestibular gland, and immediately above it the urethra. cc. Corpus cavernosum clitoridis. dG. Remains of the left Wolffian duct, such as give rise to the duct of Gärtner, represented by dotted lines; that of the right side is marked w. f. The abdominal opening of the left uterine ...
Drawing of the head of a four-week-old human embryo. From Gray's Anatomy.. Embryo drawing is the illustration of embryos in their developmental sequence.In plants and animals, an embryo develops from a zygote, the single cell that results when an egg and sperm fuse during fertilization.
The gestational sac is spherical in shape, and is usually located in the upper part (fundus) of the uterus.By approximately nine weeks of gestational age, due to folding of the trilaminar germ disc, the amniotic sac expands and occupy the majority of the volume of the gestational sac, eventually reducing the extraembryonic coelom (the gestational sac or the chorionic cavity) to a thin layer ...
Last week, a flurry of litigation in Pennsylvania clarified the rules for mail balloting there. In short, mail ballots will still be rejected in the key battleground state if voters fail to ...
In embryology, Carnegie stages are a standardized system of 23 stages used to provide a unified developmental chronology of the vertebrate embryo.. The stages are delineated through the development of structures, not by size or the number of days of development, and so the chronology can vary between species, and to a certain extent between embryos.