Myotomes

The pharyngula stage/phylotypic stage is the time when Hox gene expression is ordered and active, when organogenesis is ongoing, and when the hallmarks of chordate embryology, like segmental myotomes, a tailbud, and branchial arches are forming. ❋ Unknown (2009)

All vertebrates have a segmented body plan, but in adult mammals as opposed to embryos this is readily apparent only in the spinal region, where the vertebrae and the ribs, the blood vessels, muscle blocks myotomes and nerves all follow a pattern of modular repetition from front to back. ❋ RICHARD DAWKINS (2009)

And he said, "Gill slits and myotomes are all to no avail." ❋ Jhetley (2005)

Fat storage cells are found primarily in a distinct layer under the skin, and then in the visible sheets of connective tissue that separate the myotomes. ❋ Harold McGee (2004)

In fish, by contrast, muscle fibers are arranged in sheets a fraction of an inch thick (“myotomes”), and each short fiber merges into very thin layers of connective tissue (“myosepta”), which are a loose mesh of collagen fibers that run from the backbone to the skin. ❋ Harold McGee (2004)

And said gillslits and myotomes are all to no avail. ❋ Unknown (1920)

—The muscles of the leg like those of the arm develop in situ from the mesoderma of the leg bud, the myotomes apparently taking no part in their formation. ❋ Unknown (1918)

Cells from the posterior mass grow into the intervals between the myotomes (Fig. 65, B and C) of the corresponding and succeeding segments, and extend both dorsally and ventrally; the dorsal extensions surround the neural tube and represent the future vertebral arch, while the ventral extend into the body-wall as the costal processes. ❋ Unknown (1918)

The intrinsic muscles of the arm develop in situ from the mesoderm of the arm bud and probably do not receive cells or buds from the myotomes. ❋ Unknown (1918)

The anterior vertebral muscles, the Longus colli, Longus capitis, Rectus capitis anterior and Rectus capitis lateralis are derived from the ventral part of the cervical myotomes as are probably also the Scaleni. ❋ Unknown (1918)

The shorter muscles, such as the Interspinales, Intertransversarii, the deeper layers of the Multifidus, the Rotatores, Levatores costarum, Obliquus capitis inferior, Obliquus capitis superior and Rectus capitis posterior minor which extend between adjoining vertebræ, retain the primitive segmentation of the myotomes. ❋ Unknown (1918)

—The intrinsic muscles of the trunk which are derived directly from the myotomes are conveniently treated in two groups, the deep muscles of the back and the thoraco-abdominal muscles. ❋ Unknown (1918)

The thoraco-abdominal muscles arise through the ventral extension of the thoracic myotomes into the body wall. ❋ Unknown (1918)

The intrinsic muscles of the trunk are derived from the myotomes while the muscles of the head and limbs differentiate directly from the mesoderm. ❋ Unknown (1918)

Before throwing tail and hinder part of body away, note the myotomes of body wall, the notochord and vertebral body, neural canal, and, in the tail, the haemal canal. ❋ Unknown (1906)

Both sets are segmented, and consist of a double row of muscular plates (Figures 1.98 and 1.99 ms); the number of these myotomes determines the number of joints in the trunk, or metamera. ❋ Ernst Heinrich Philipp August Haeckel (1876)

In the latter the chief part of the skeleton -- the vertebral column and skull -- develops from this chord-sheath; in the acrania it retains its simple form as a soft connective matter, from which are formed the membranous partitions between the various muscular plates or myotomes (Figures 1.98 and 1.99 ms). ❋ Ernst Heinrich Philipp August Haeckel (1876)