myotome

anatomy

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July 1, 2026

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A myotome is the portion of an embryonic somite that develops into skeletal muscle. Somites are blocklike segments formed from the mesoderm, the middle tissue layer, along the sides of the developing spine in an embryo. These somites give rise to various structures, including the myotome, which is the source of the major muscles in vertebrates. Myoblasts, which are primitive muscle cells, differentiate from somite tissue to form voluntary muscle fibers. The term "myo-" itself means muscle.1234

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9 Britannica Sources

myotome
somite
prenatal development - Muscular system
dermatome
nervous system disease - Electromyography
dermatome
nervous system disease - Muscle
human nervous system - Structural components of spinal nerves
my-

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- somite
  …of the skin; and the myotome, or primitive muscle, from which the major muscles of vertebrates are derived. The term somite is also used more generally to refer to a body segment, or metamere, of a segmented animal.
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  …of the skin; and the myotome, or primitive muscle, from which the major muscles of vertebrates are derived. The term somite is also used more generally to refer to a body segment, or metamere, of a segmented animal.
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- amphioxus
  …contracting the muscle blocks, or myotomes, that run from end to end on each side of the body. The blocks on each side are staggered, producing a side-to-side movement of the body when swimming. Amphioxi are not buoyant, and they sink quickly when they stop swimming. A dorsal fin runs…
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  …contracting the muscle blocks, or myotomes, that run from end to end on each side of the body. The blocks on each side are staggered, producing a side-to-side movement of the body when swimming. Amphioxi are not buoyant, and they sink quickly when they stop swimming. A dorsal fin runs…
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animal development
The body muscles and axial skeleton
…upper, dorsolateral part called the myotome remains compact, giving rise to the body muscles. The lower, medioventral part of the somite, called the sclerotome, breaks up into mesenchyme, which contributes to the axial skeleton of the embryo—that is, the vertebral column, ribs, and much of the skull. The parietal layer…
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…upper, dorsolateral part called the myotome remains compact, giving rise to the body muscles. The lower, medioventral part of the somite, called the sclerotome, breaks up into mesenchyme, which contributes to the axial skeleton of the embryo—that is, the vertebral column, ribs, and much of the skull. The parietal layer…
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nervous system
The primitive condition
…the adjacent body segments called myotomes. The dorsal and ventral roots remain separate nerves and arise at alternate positions along the cord. In lower fishes there is still alternation of dorsal and ventral roots, but the roots unite in a single spinal nerve. In higher vertebrates the two roots unite…
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…the adjacent body segments called myotomes. The dorsal and ventral roots remain separate nerves and arise at alternate positions along the cord. In lower fishes there is still alternation of dorsal and ventral roots, but the roots unite in a single spinal nerve. In higher vertebrates the two roots unite…
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