somite


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somite

 [so´mīt]
one of the paired segments along the neural tube of a vertebrate embryo, formed by transverse subdivision of the thickened mesoderm next to the midplane, that develop into the vertebral column and muscles of the body.
Somites in a 22-day embryo. From Dorland's, 2000.

so·mite

(sō'mīt),
One of the paired, metamerically arranged cell masses formed in the early embryonic paraxial mesoderm; commencing in the third or early fourth week in the region of the hindbrain, they develop in a caudal direction typically until 42 pairs are formed.
Synonym(s): mesoblastic segment
[G. sōma, body, + -ite]

somite

/so·mite/ (so´mīt) one of the paired, blocklike masses of mesoderm, arranged segmentally alongside the neural tube of the embryo, forming the vertebral column and segmental musculature.

somite

(sō′mīt′)
n.
1. Any of the homologous segments that compose the body of certain animals, such as earthworms and lobsters, and are arranged in a longitudinal series.
2. A segmental mass of mesoderm in the vertebrate embryo, occurring in pairs along the notochord and developing into muscles and vertebrae.

so·mit′ic (sō-mĭt′ĭk) adj.

somite

[sō′mīt]
Etymology: Gk, soma, body
any of the paired segmented masses of mesodermal tissue that form along the length of the neural tube during the early stage of embryonic development in vertebrates. These structures give rise to the vertebrae and differentiate into various tissues of the body, including the voluntary muscle, bones, connective tissue, and dermal layers of the skin. The first somite to appear is in the future occipital region, and the formation of new somites continues in a caudal direction until 36 to 38 have developed.

so·mite

(sō'mīt)
One of the paired, metamerically arranged cell masses formed in the early embryonic paraxial mesoderm; commencing in the third or early fourth week in the region of the hindbrain, they develop in a caudal direction until 42 pairs are formed; their presence is considered evidence that metameric segmentation is a vertebrate characteristic.
[G. sōma, body, + -ite]

somite

or

metamere

a serial segment of the animal body. see METAMERIC SEGMENTATION.

so·mite

(sō'mīt)
One of the paired, metamerically arranged cell masses formed in early embryonic paraxial mesoderm; develop in a caudal direction typically until 42 pairs are formed.
[G. sōma, body, + -ite]

somite

one of the paired block-like masses of mesoderm beside the neural tube of a vertebrate embryo, formed by transverse subdivision, that develop into the vertebral column, skin and muscles of the body.
References in periodicals archive ?
It differs from the known six, conspecific subspecies in the combination of the following characters: structure of exopodite of antennae and mandibular palp, presence of inner seta on the first segment of legs 2, and equipment of abdominal somites.
The Dmrt2 gene is expressed in gonadal tissues with species difference, as well as in some nongonadal tissues such as somites (Meng et al.
2003), the more invasive procedure of somite cross-transplantation was not attempted in the previous study.
Students use dowels to roll out sheets of blue ectoderm to represent skin and red mesoderm to represent somites, as well as rolling long cylinders representing spinal cord (green neural ectoderm), notochord (red mesoderm), and gut (yellow endoderm).
It occurs due to the failure of normal segmentation of cervical somites in weeks 3 to 8 of gestation.
First four tergal somites of the opisthosoma not demarcated externally except by patterns of tubercles and coloration, tergite 5 distinguished anteriorly by incomplete transverse groove, tergites 6, 7, 8 + 9 and anal operculum demarcated by transverse grooves.
Typically, KFS results from failure of the normal segmentation of the somites during weeks 3 to 8 of gestation.
By 84 hours, the retina was pigmented, and somites and the pectoral fin were developed.
The basal support for the hindbrain is provided by parachordals that are formed from the sclerotome portion of anterior somites.
They are derived from the neuroblastic anlage associated with the dorsal roots of vertebral somites or primitive cells associated with cranial nerve ganglia.
3, 4A) are elongate with a cephalothoraxial region covered by a carapace, an abdomen consisting of six somites, and a tail fan (telson).