| Name: | cleithrum | 
|---|---|
| Synonyms: | cleithra | 
| Definition: | Transversely oriented bone connecting the occipital region of the skull dorsally and pectoral girdle ventrally; appears near the end of embryogenesis. | 
| Ontology: | Anatomy Ontology [ZFA:0000184] | 
| Name: | osteoblast | 
|---|---|
| Synonyms: | osteoblasts | 
| Definition: | A bone-forming cell which secretes an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone. | 
| Ontology: | Anatomy Ontology [ZFA:0009031] |