Search results
Results from the WOW.Com Content Network
Development before birth, or prenatal development (from Latin natalis 'relating to birth') is the process in which a zygote, and later an embryo, and then a fetus develops during gestation. Prenatal development starts with fertilization and the formation of the zygote , the first stage in embryonic development which continues in fetal ...
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 36 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus .
Cortical white matter increases from childhood (~9 years) to adolescence (~14 years), most notably in the frontal and parietal cortices. [8] Cortical grey matter development peaks at ~12 years of age in the frontal and parietal cortices, and 14–16 years in the temporal lobes (with the superior temporal cortex being last to mature), peaking at about roughly the same age in both sexes ...
Physical development. Infants are usually born weighing between 5 pounds 8 ounces (2,500 g) and 8 pounds 13 ounces (4,000 g), but infants born prematurely often weigh less. [17] Newborns typically lose 7–10% of their birth weight in the first few days, but they usually regain it within two weeks. [17]
Fertilization of the ovum to form a new human organism, the human zygote. (day 1 of fertilization [1]) The zygote undergoes mitotic cellular divisions, but does not increase in size. This mitosis is also known as cleavage. A hollow cavity forms marking the blastocyst stage. (day 1.5–3 of fertilization. [1])
Lungs and thin, moist skin allowed them to breathe; water was also needed to give birth to shell-less eggs and for early development. Dorsal, anal and tail fins all disappeared. Lissamphibia (extant amphibians) retain many features of early amphibians but they have only four digits (caecilians have none). 330-300 Ma Hylonomus
Prenatal development (from Latin natalis ' relating to birth ') involves the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization , in the germinal stage of embryonic development, and continues in fetal development until birth .
Brain areas that undergo significant post-natal development, such as those involved in memory and emotion are more vulnerable to effects of early life stress. [58] [64] For example, the hippocampus continues to develop after birth and is a structure that is affected by childhood maltreatment. [64]