Term: heart primordium presumptive endocardium
Name: heart primordium
Synonyms: cardiac field, heart primordia
Definition: Bilateral groups of cells consisting of three rows: one row of endocardial precursors medially and two rows of myocardial precursors laterally. The two populations fuse at the midline between 21 and 26 somites to form the heart rudiment or cone.
Ontology: Anatomy Ontology [ZFA:0000028]

Name: presumptive endocardium
Synonyms:
Definition: Portion of tissue that is part of the heart tube and will become the endocardium.
Ontology: Anatomy Ontology [ZFA:0001724]