Embryogenesis is a comprehensive term used in the process of embryonic formation in the biological world. It is mostly used in animals, but in plants, generally on plants above the moss (with embryo plants), it means that the single-cell fertilized eggs in the ovary blastocyst develop into more than one. The term is also used in the process of cell embryos, in which the fertilized egg grows and differentiates significantly from spores. In some cases, it is also expanded to grow and differentiate after the whole plant zygote (C.W. Wardlaw). From the morphological aspect of studying the occurrence and development of embryos, it is called embryogenesis.
The embryo is a larval within the first two months of pregnancy. The early development of blastocysts, embryos and embryonic development is a continuous process. During the body festival, all three germ layers changed. The ectoderm is recessed into a groove in the midline of the back, called the nerve groove, and the two sides of the groove are called nerve ridges. The nerve ridge gradually approaches and heals, causing the nerve to evolve into a neural tube that runs through the embryo body. The neural tube and nerve ridge will evolve into the nervous system in the future. The endoderm is curled into a tubular shape with the embryo body, which is called the gut. The gut is divided into the foregut, the midgut and the hindgut.
Generally, eggs are called pregnant or fertilized eggs within 2 weeks after fertilization; embryos are called embryos 3 to 8 weeks after fertilization. From a fertilized egg to a new individual, going through a series of very complex changes, here is a brief introduction to the development of the embryo. After fertilization, the egg cells begin to divide and develop and form embryos. The first embryo formed is a morula (the shape of the embryo is like a mulberry), and then the blastocyst is formed (the embryo is sac) and implanted in the endometrium to absorb the nutrients of the mother and continue to develop. The blastocyst wall is a trophoblast with an inner cell mass. The embryo continues to develop, and a part of the inner cell mass develops into three germ layers: ectoderm, endoderm, and mesoderm, and then the three germ layers differentiate to develop all tissues and organs of the adult body.
Reasons for stopping development
Antisperm antibody (ASAB) and embryos are stopped, antisperm antibodies act on phospholipids on uterine placental vascular endothelial cells, damage vascular endothelial cells, platelet aggregation, thrombosis, insufficient blood supply to sputum or placenta, and fetal arrest Education. Antisperm antibodies can also cause fetal arrest by interfering with embryo implantation, development, and placental formation. Anti-endometrial antibodies are autoantibodies that target the endometrium and cause pathological reactions. Anti-endometrial antibodies (EMAB) bind to antigens in the endometrium, activate complement, and cause endometrial cytotoxicity. Damage effect, anti-implantation effect on pregnant eggs, causing infertility or miscarriage, when endometritis or endometriosis, endometrial tissue may be converted into antigen or hapten to stimulate the body to synthesize anti-endometrial antibodies.
Serum prolactin is a polypeptide hormone secreted by the anterior pituitary. If the pituitary dysfunction or space-occupying lesions can occur hyperprolactinemia, inhibit the synthesis and release of hypothalamic gonadotropin, cause follicular development and ovulation disorders, and interfere with fertilization and embryonic development, leading to infertility or fetal arrest Education. In normal pregnancy, with the development of fertilized eggs, the villus secretes human chorionic gonadotropin, and the function of the corpus luteum is further improved. When the corpus luteum is incomplete, progesterone secretion is affected, which will affect the normal development of the embryo.