23.3: Embryonic Stage - Biology LibreTexts
After a blastocyst implants in the uterus around the end of the first week after fertilization, its internal cell mass, which was called the embryoblast, is now known as the embryo. The embryonic stage lasts through the eighth week following fertilization, after which the embryo is …
Fetal Development: Week-by-Week Stages of Pregnancy - Cleveland Clinic
The fetal stage of development begins around the ninth week and lasts until birth. This is when the embryo officially turns into a fetus. The fetus gets its assigned sex around nine weeks of pregnancy, although your healthcare provider can’t detect it on ultrasound yet.
3 Prenatal Development Stages - Verywell Mind
2024年5月20日 · The first stage, known as the germinal stage, involves the formation of the zygote and early cell division. The second stage, called the embryonic stage, involves the early growth of the embryo, including the formation of the neural tube, which will eventually become the brain and spinal cord.
Embryonic Development - Embryology
4 天之前 · Use the stage number links to images and information about each specific stage of human development over the first 8 weeks. The links below give a broad overview of developmental events during each week.
28.2 Embryonic Development – Anatomy & Physiology
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 - Wikipedia
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.
Stages of Fetal Development - Stages of Fetal Development
The next stage in development is the embryo, which develops within the amniotic sac, under the lining of the uterus on one side. This stage is characterized by the formation of most internal organs and external body structures.
Prenatal development | Description, Stages, & Timeline | Britannica
Prenatal development, the process encompassing the period from the formation of an embryo, through the development of a fetus, to birth. This process can be divided into three distinct stages: the pre-embryonic stage, the embryonic period, and the fetal period.
Embryo - Definition, Development, Stages and Quiz - Biology …
2017年7月6日 · In humans, the embryonic stage of development is defined as the period from week 5 to week 11 of gestation. After this stage, the embryo transitions into a fetus. In plants, the process of embryogenesis extends from the time of fertilization until dormancy.
14.3: Embryonic Development - Biology LibreTexts
2022年7月30日 · 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 …