| Name: | notochord |
|---|---|
| Synonyms: | notocord |
| Definition: | Rod-like principal supportive element of the embryo and larva, present in the midline just ventral to the neural tube, and differentiating during the segmentation period to form large vacuolated epithelial cells and a surrounding sheath of fibrous and elastic layers. Layering of the sheath may differ in structure, thickness and development among groups; in cypriniforms there are actually three very thin layers to the sheath. A functional, well developed notochord is present throughout life in certain basal fish groups but not in cypriniforms. |
| Ontology: | Anatomy Ontology [ZFA:0000135] |
| Name: | cell |
|---|---|
| Synonyms: | cells |
| Definition: | Anatomical structure that has as its parts a maximally connected cell compartment surrounded by a plasma membrane. |
| Ontology: | Anatomy Ontology [ZFA:0009000] |
| Name: | orientation |
|---|---|
| Synonyms: | amount of rotation, angle, angular magnitude, angular placement, plane angle |
| Definition: | A spatial quality inhering in a bearer by virtue of the bearer's placement which is defined by the angle between the bearer and an axis, or the angle between the bearer and another object. |
| Ontology: | Phenotypic Quality Ontology [PATO:0000133] |