American Heritage® Dictionary of the English Language, Fourth Edition
- n. A flexible rodlike structure that forms the main support of the body in the lowest chordates, such as the lancelet; a primitive backbone.
- n. A similar structure in embryos of higher vertebrates, from which the spinal column develops.
Century Dictionary and Cyclopedia
- n. The chorda dorsalis or primitive backbone: a fibrocellular or cartilaginous rod-like structure which is developed in vertebrates as the basis of the future spinal column, and about which the bodies of the future vertebræ are formed. It is one of the earliest embryonic structures, and persists throughout life in many of the lower vertebrates, which are on this account called notochordal; but in most cases it is soon absorbed and replaced by a definite cartilaginous or bony spinal column. The soft pulpy substance which may be seen filling in the cupped ends of the vertebrw of a fish, as brought to the table, is a part or the remains of the notochord. Anteriorly, in skulled vertebrates, the notochord runs into the base of the skull as far as the pituitary fossa. (see
parachordal.) The caudal division of a notochord is often called urochord. Such a structure is characteristic of tunicates or ascidians, called on this account Urochorda, and approximated to or included among vertebrates. (See Appendiculariidæ.) A sort of notochord occurring in the acorn-worms has caused them to be named Hemichorda. (See Balanoglossusand Enteropneusta.) The lancelets are named Cephalochorda with reference to the extension of this structure into the head. See Chordata, and cuts under Pharyngobranchii, chondrocranium, Lepidosiren, and visceral.
- n. A vestigial structure, representing a very ancient form of alimentary canal not in itself a part of the skeleton.
- n. A flexible rodlike structure that forms the main support of the body in the lowest chordates; a primitive spine
- n. A similar structure found in the embryos of vertebrates from which the spine develops
GNU Webster's 1913
- n. (Anat.) 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 vertebræ and the posterior part of the base of the skull are developed; the
chorda dorsalis. See Illust.of ectoderm.
- n. 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
- Greek nōton, back + chord2. (American Heritage® Dictionary of the English Language, Fourth Edition)
“For example, the notochord is a character that provides internal structural support and unites all members of the phylum Chordata or chordates, animals with notochords and pharyngeal arches, among other characteristics.”
“A notochord is a rope of nervous connection which branches into the trunk nerves of the body.”
“Thus the notochord is the necessary forerunner of the vertebral column, cartilage the precursor of bone.”
“The notochord is a continuous rod of cartilage, or gristle, which in the embryological growth of vertebrate animals supports the spinal nerve cord before the formation of the vertebrae.”
“The notochord is the supporting axis of the pioneer backboned animals, namely the Lancelets and the Round-mouths (Cyclostomes), such as the”
“Concomitantly with the development of this canal, there is found, immediately beneath it, a little gelatinous rod enclosed in a membraneous envelope, and called the notochord, or chorda dorsalis.”
“Amphioxus has only a primitive proto-spinal column called a notochord, but it is a very close relative of vertebrates.”
“Amphioxus has only a primitive proto-spinal column called a notochord, but it is a very close relative of the vertebrates.”
“The finding is of particular relevance to the fossils of ancient chordates - animals that develop a characteristic rod-like support structure known as a notochord at some point during their lives.”
“O. Mangold was able to show that mesodermal organs such as notochord, somites and pronephric ducts could arise from presumptive ectoderm by suitable transplantation at the beginning of gastrulation.”
These user-created lists contain the word ‘notochord’.
Yet more spelling words for intermediate to advanced spellers.
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the back; dorsum
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A somewhat discriminatory list of words and phrases collected for their euphonic or arcane appeal, interesting etymology, or concise definition of an otherwise unnamed phenomenon or concept.
Words that have only one of the vowels. On this list I include only words with at least three vowels. When I first started the list, if a word had several forms, I generally listed only the one wit...
need to know these words!!!!!!!!!!!!!!
monovocalic with 'o' but ONLY if I like them :-)
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