Elements of human physiology (1907) Elements of human physiology elementsofhumanp05star Year: 1907 70 PHYSIOLOGY those destroyed and discharged to form l)ilo and urinary pigments. There is considerable doubt as to the exact mode and place in which this regeneration occurs, and the process seems to be quite different according as we consider the foetal or adult condition. We may therefore consider first the formation of red corpuscles in the eml)ryo and new-l)orn animal. The red corpuscles at an early stage of fontal life are nucleated, like those of the frog or l)ird. Li the vascular area of
Elements of human physiology (1907) Elements of human physiology elementsofhumanp05star Year: 1907 70 PHYSIOLOGY those destroyed and discharged to form l)ilo and urinary pigments. There is considerable doubt as to the exact mode and place in which this regeneration occurs, and the process seems to be quite different according as we consider the foetal or adult condition. We may therefore consider first the formation of red corpuscles in the eml)ryo and new-l)orn animal. The red corpuscles at an early stage of fontal life are nucleated, like those of the frog or l)ird. Li the vascular area of the chick, nests of nuclei are found embedded in Fig. 22. a -' ,„ Section of red marrow of mammal (Bohm and Davidoff). a, e, ery- throblasts ; b, reticulum ; c, mj'eloplax; c7, g, marrow cells; /, a marrow cell dividing ; li, a space which was occupied by fat. colourless masses of non-difierentiated protoplasm. A little later it is seen that these nuclei are all surrounded with a differentiated portion of the protoplasm, which now con- tains hemoglobin, the intervening undifferentiated portions having become more fluid and representing the future blood-plasma. Very soon the masses of protoplasm become channelled and connected with one another and with the large vessels coming from the heart, and the fully formed blood moves on into the general circulation in response to the heart-beat. According to Schafer, non-nucleated blood-discs may be
Size: 1851px × 1081px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
