<unk> s (from Greek threphein: to feed) are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg.
Trophoblast
Immunoblast
Ameloblast
Odontoblast
Chondroblast
Lymphoblast
Normoblast
Stem cell