An embryo is the initial stage of development for a multicellular organism. In organisms that reproduce sexually , embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell .

2023年4月12日 · During each week of pregnancy, your baby is growing. Here’s a look at what medical terms like embryo and fetus mean in terms of development.

2023年8月13日 · An embryo refers to the early developmental stage of a multicellular organism that follows fertilization. This stage represents a crucial juncture in the life cycle, transitioning from a single fertilized cell into a complex organism with specialized tissues and structures.

2021年8月25日 · The embryo (and later the fetus) is reliant on the pregnant person’s blood (which carry oxygen and nutrients) through the placenta. The placenta is an organ specially formed from the blastocyst cell layer called the trophectoderm (3).

2025年2月9日 · An embryo is the early developmental stage of an animal while it is in the egg or within the uterus of the mother. In humans the term is applied to the unborn child until the end of the seventh week following conception.

2017年7月6日 · 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.

For fertilization (conception), spermatozoa (male haploid gametes) migrate through the cervical canal, the uterine cavity, and into the fallopian tubes. In the ovary, follicles develop and, during ovulation, the dominant follicle releases an oocyte (female haploid gamete).

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.

2023年8月3日 · Human embryogenesis refers to the development and formation of the human embryo. It encompasses the first eight weeks of development after fertilization, in which a single cell formed at fertilization turns into an organism with a multi-level body plan.

Fluid, oxygen, and nutrients pass across the membrane from the mother to the embryo, and carbon dioxide and waste products pass from the embryo to the mother. Cells from the placenta also develop into the amniotic sac. Two layers of membranes form around the embryo: the amnion (inner membrane) and chorion (outer membrane).