title: The ultrastructure of the ultimobranchial body in the rat.
mesh_terms: D000818:Animals; D004702:Endocrine Glands / Q000166:cytology / Q000201:enzymology*; D008854:Microscopy, Electron; D051381:Rats; D013961:Thyroid Gland / Q000166:cytology / Q000196:embryology*