. Human embryology and morphology. Embryology, Human; Morphology. THE SPINAL COLUMN AND BACK. 147 chord is enclosed in the suspensory ligament. The body of each vertebra is formed round the notochord and at first each has an hour-glass canal surrounding the notochord. Within each pituitary ~—basi-sphen. basi-occip. suspensory lig. axis. interuert. disc, centre of disc. fr-C -coccyx. Fig. 117.—Where Remnants of the Notochord may occur in the Adult. vi body the notochord ultimately disappears but in the inter- vertebral discs it swells out and forms much of the central mucoid core which each dis
. Human embryology and morphology. Embryology, Human; Morphology. THE SPINAL COLUMN AND BACK. 147 chord is enclosed in the suspensory ligament. The body of each vertebra is formed round the notochord and at first each has an hour-glass canal surrounding the notochord. Within each pituitary ~—basi-sphen. basi-occip. suspensory lig. axis. interuert. disc, centre of disc. fr-C -coccyx. Fig. 117.—Where Remnants of the Notochord may occur in the Adult. vi body the notochord ultimately disappears but in the inter- vertebral discs it swells out and forms much of the central mucoid core which each disc contains. The notochord with its membranous sheath is the earliest form of spinal column known. The real vertebral column, formed out of its sheath, begins to supplant it even in low vertebrates and in the human foetus of the second month this change is also seen to take place. Proto-vertebrae or Primitive Segments.—Proto-vertebrae are not the forerunners of the vertebrae; they are the primitive segments into which the mass of mesoblast at each side of the neural canal and notochord divides (Figs. 233, p. 289 and 116). The process of division or segmentation begins at the occipital region towards the end of the second week and spreads backwards until 3 5 or more body segments or somites are cut off. Each segment thus separated forms its own muscles (from its muscle. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Keith, Arthur, Sir, 1866-1955. London : E. Arnold
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
