notochord

n. spinal cord (Biology)

The notochord is a flexible, rod-shaped body found in embryos of all chordates. It is composed of cells derived from the mesoderm and defines the primitive axis of the embryo. In lower vertebrates, it persists throughout life as the main axial support of the body, while in higher vertebrates it is replaced by the vertebral column. The notochord is found on the ventral surface of the neural tube.
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Noun
1. 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
(hypernym) spinal column, vertebral column, spine, backbone, back, rachis
(hyponym) urochord

(n.)
An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebrae and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm.
  

NOTOCORDA