. The anatomical record. Anatomy; Anatomy. 262 RUTH RAND ATTERBURY transection; see description of figure) in a high-power drawing, figure 7. Although the origin of the bursa pharyngea in the human embryo is undoubtedly closely bound up with noto- chordal contact, still the picture suggests that the development of the bursa is due to the tension exerted not merely by the notochord alone, but equally by the sheath of developing con- nective tissue about the notochord. This sheath of connective tissue is later incorporated with the fascia pharyngobasilaris. It is possible, however, that notochor
. The anatomical record. Anatomy; Anatomy. 262 RUTH RAND ATTERBURY transection; see description of figure) in a high-power drawing, figure 7. Although the origin of the bursa pharyngea in the human embryo is undoubtedly closely bound up with noto- chordal contact, still the picture suggests that the development of the bursa is due to the tension exerted not merely by the notochord alone, but equally by the sheath of developing con- nective tissue about the notochord. This sheath of connective tissue is later incorporated with the fascia pharyngobasilaris. It is possible, however, that notochordal contact may influence the mesenchyme to condense earlier to form the sheath, since. ^M ?ieja*. Fig. 7 Human embryo, 46 mm. C. B. length (no. 93Hb., Cornell Collection) twin to the embryo from which figure 6 was drawn, cut in the horizontal plane. The bursa pharyngea is shown cut nearlj^ transversely. A portion of the basilar plate is shown. To show the relation of the bursa to the surrounding connective tissue. X 100. the fibers seem to appear in the human embryo at a relatively earlier stage thay in the calf and the pig. In conclusion, it is advisable to emphasize again the me- chanical nature of the pharyngeal outpocketings in the calf (when present) pig, and human embryos. These structures are merely mechanical expressions of the growth conditions of the pharyn- geal region, arising in accordance with the presence of the me- chanical factors determining them. The bursa pharyngea of man therefore cannot be considered a structure of fundamental sig- nificance, essential to the development of the pharyngeal tonsil,. 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 Bardeen, Charles Russell, 1871-1935, ed; Boyden, Edward A. (Edward Allen), 1886-1976; Bremer, John Lewis, 1874- ed; Hardesty, Irving, b. 1866,
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1906
