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A developing human is referred to as an embryo during weeks 3–8, and a fetus from the ninth week of gestation until birth. In this section, we’ll cover the pre-embryonic and embryonic stages of development, which are characterized by cell division, migration, and differentiation.
Human embryonic development or human embryogenesis is the development and formation of the human embryo. It is characterised by the processes of cell division and cellular differentiation of the embryo that occurs during the early stages of development.
This page shows some key events of human development during the embryonic period of the first eight weeks (weeks 1 - 8) following fertilization. This period is also considered the organogenic period, when most organs within the embryo have begun to form.
There are three stages of fetal development: germinal, embryonic and fetal. Most people don’t talk about their pregnancy in these terms, but it can be helpful to know. Germinal stage. The germinal stage is the shortest stage of fetal development. It begins at conception when a sperm and egg join in your fallopian tube.
Genetic and Environmental Risks to Embryonic Development. The embryonic stage is a critical period of development. Events that occur in the embryo lay the foundation for virtually all of the body’s different cells, tissues, organs, and organ systems.
In this section, we’ll cover the pre-embryonic and embryonic stages of development, which are characterized by cell division, migration, and differentiation. By the end of the embryonic period, all of the organ systems are structured in rudimentary form, although the organs themselves are either nonfunctional or only semi-functional.
Jul 6, 2017 · An embryo refers to the early developmental stage of eukaryotic organisms following the fertilization of an egg (derived from a female) by sperm (derived from a male) as a method of sexual reproduction.
The Basics. Embryology. In our article on weeks 1-3 of embryonic development you’ll learn that the first stage of development starts off with fertilisation. This is the process of male sperm fusing with the female ovum and it’s the basis of the embryology covered in the article.
Key terms. What happens during pregnancy? Have you ever wondered why a typical human pregnancy lasts about 9 months? What goes on in there? Do all animals carry their babies for 9 months? 20 22. The embryo develops within the womb during this period. First, stem cells in the inner cell mass of the implanted blastocyst begin to differentiate.
Mar 17, 2021 · Early in development, human embryos form a structure called the blastocyst. Two research groups have now generated human blastocyst-like structures from cells in a dish, providing a valuable...
