Ectoderm

All you want to know about Ectoderm

Ectoderm

Organs derived from ectoderm.

Section through embryonic disk of Vespertilio murinus.
Gray's	subject #6 48
Days	16
MeSH	Ectoderm

The ectoderm is the start of a tissue that covers the body surfaces. It emerges first and forms from the outermost of the germ layers.

Generally speaking, the ectoderm differentiates to form the nervous system, epidermis, and the outer part of integument.

In vertebrates, the ectoderm has three parts: external ectoderm (also known as surface ectoderm), the neural crest, and neural tube. The latter two are known as neuroectoderm.

Section through ovum imbedded in the uterine decidua

v • d • e Developmental biology > Human embryogenesis (development of embryo) and development of fetus (some dates are approximate - see Carnegie stages and a timeline)

Week 1	Fertilization - Egg activation - Zygote - Cleavage - Morula - Blastula (Blastomere) - Blastocyst - Inner cell mass

Week 2	Bilaminar disc (Hypoblast, Epiblast)

Week 3 (Trilaminar embryo, germ layers)	Archenteron/Primitive streak (Primitive pit, Primitive knot/Blastopore, Primitive groove) - Gastrula/Gastrulation - Regional specification Ectoderm: Surface ectoderm - Neuroectoderm - Somatopleure - Neurulation - Neural crest Endoderm: Splanchnopleure Mesoderm: Chorda- - Paraxial (Somite/Somitomere/Sclerotome/Myotome/Dermatome) - Intermediate - Lateral plate (Intraembryonic coelom, Splanchnopleure/Somatopleure)

Extraembryonic/uterus	Trophoblast (Cytotrophoblast, Syncytiotrophoblast) Blastocoele - Yolk sack/exocoelomic cavity - Heuser's membrane - Extraembryonic coelom - Vitelline duct Umbilical cord (Umbilical artery, Umbilical vein, Wharton's jelly) - Allantois Placenta - Decidua (Decidual cells) - Chorionic villi/Intervillous space - Gestational sac (Amnion/Amniotic sac/Amniotic cavity, Chorion)

Histogenesis	Programmed cell death (Apoptosis) - Stem cells - Germ line development

Organogenesis	Limb development: Limb bud - Apical ectodermal ridge/AER other structures: Eye development - Cutaneous structure development - Heart development - Development of the urinary and reproductive organs