Notochord (Noun)
Meaning
A flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates.
Classification
Nouns denoting animals.
Examples
- The notochord serves as a primary support structure in the development of vertebrates before the vertebral column is formed.
- In embryonic development, the notochord is surrounded by the vertebral column that gradually replaces its supportive function.
- The notochord is composed of a solid core of mesodermal cells that is surrounded by a sheath of connective tissue.
- Tunicates and some other invertebrate chordates possess a notochord throughout their lives, while it eventually gives way to a vertebral column in vertebrates.
- Comparative anatomy and embryonic studies have established the notochord as a key feature in understanding vertebrate body plan evolution.