Editing Germ layer (section)

===Ectoderm===
[[Image:Ectoderm.png|thumb|250px|The [[ectoderm]] produces tissues within the [[Epidermis (skin)|epidermis]], aids in the formation of [[neuron]]s within the brain, and constructs [[melanocytes]].]]
{{main|Ectoderm}}
The '''ectoderm''' generates the outer layer of the embryo, and it forms from the embryo's [[epiblast]].<ref>{{cite book | title = Developmental Biology | chapter = Early Mammalian Development | first = Scott F | last = Gilbert | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK10052/#A2620 | publisher = Sinauer Associates | year = 2003}}</ref> The [[ectoderm]] develops into the [[surface ectoderm]], [[neural crest]], and the [[neural tube]].<ref>{{cite book | title = Developmental Biology | chapter = The Central Nervous System and The Epidermis | first = Scott F | last = Gilbert | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK10026/figure/A2869/ | publisher = Sinauer Associates | year = 2003}}</ref>

The surface ectoderm develops into: [[epidermis (skin)|epidermis]], [[hair]], [[nail (anatomy)|nails]], [[lens of the eye]], [[sebaceous glands]], [[cornea]], [[tooth enamel]], the epithelium of the [[mouth]] and [[nose]].

The neural crest of the ectoderm develops into: [[peripheral nervous system]], [[adrenal medulla]], [[melanocytes]], facial cartilage.

The neural tube of the ectoderm develops into: [[brain]], [[spinal cord]], [[posterior pituitary]], [[motor neurons]], [[retina]].

Note: The anterior pituitary develops from the ectodermal tissue of [[Rathke's pouch]].

====Neural crest====

Because of its great importance, the neural crest is sometimes considered a fourth germ layer.<ref>{{cite journal |author=Hall BK |s2cid=27150120 |year=2000 |title=The neural crest as a fourth germ layer and vertebrates as quadroblastic not triploblastic |journal=Evolution & Development |pmid=11256415 |volume=2 |issue=1 |pages=3–5 |doi=10.1046/j.1525-142x.2000.00032.x}}</ref> It is, however, derived from the ectoderm.