. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. Child. Ant. EXTBEMrrr I^J-RlB. Aduu. CniLO Fiff. IV. Fig. V. Fig. IV. Diagram to show the clavicular auglein the child and the adult; and also the descent of the anterior end of the first rib. The clavicular angles shown are of the average number of degrees. The descent of the rib is entirely diagrammatic. The figure is intended to show that as the shoulder sinks it tends to stretch the lowest brachial trunk over the first rib. The rib itself also tilts downwards, and thus in the normal subject nullifies the tendency
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. Child. Ant. EXTBEMrrr I^J-RlB. Aduu. CniLO Fiff. IV. Fig. V. Fig. IV. Diagram to show the clavicular auglein the child and the adult; and also the descent of the anterior end of the first rib. The clavicular angles shown are of the average number of degrees. The descent of the rib is entirely diagrammatic. The figure is intended to show that as the shoulder sinks it tends to stretch the lowest brachial trunk over the first rib. The rib itself also tilts downwards, and thus in the normal subject nullifies the tendency to stretching of the nerve by allowing it to travel to its distribution with a less marked upward curve. It will be seen that the compensation is normally less marked in women. Fig. V. Diagram to show how descent of the first rib in growth from infancy to adult age compensates the stretching effect of the descent of the shoulder on the nerve. The curved black line represents the vertebral column. The straight black lines represent the first rib in childhood and in adult age. The costal angles are given in degrees. C represents the position of the inner end of the clavicle in infancy and in adult age. The black circle N represents the crossing of the first rib by the lowest brachial trunk. It will be seen that while the descent of the shoulder tends to lengthen the course which the nerve must pursue to reach its distribution, the descent of the first rib tends to shorten the course of the nerve by allowing it to pass in more direct manner to its distribution. Thus, in the majority of cases, the descent of the first rib compensates the descent of the shoulder. is made for this by the slight sigmoid course of the nerve as it passes over the first rib (4).. 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 Anatomi
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherjenag, bookyear1912
