birth and infancy
type: Concept
narrower: embryo

branchial region
type: Concept
broader: embryo

concepts
type: Collection
type: ConceptGroup
member: embryo

embryo
type: Concept
broader: embryonic structures
broader: birth and infancy
definition: During the 46-day embryo stage, the embryo grows to a length of more than 1 inch (2.5 cm). By the end of the embryo stage, many body systems will be in operation and the embryo will begin to appear humanlike. [Source: Encyclopedia of Human Development; Embryo]
narrower: notochord
narrower: branchial region

embryonic structures
type: Concept
narrower: embryo

notochord
type: Concept
broader: embryo