. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. V V. FIGURE 5. Diagram showing two ways in which arterial capillaries (stippled) and venous capillaries (white) may be arranged in a rete mirahile. countered. \Ye have not done serial sections, and cannot say whether these pack- ing-patterns persist unchanged along the length of the rete. An important aspect of retial structure, which must he taken into account in formulating any theory of the action of the counter-current system is that the choroid rete is not uniform along the length of the capillaries. In longitudinal sec
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. V V. FIGURE 5. Diagram showing two ways in which arterial capillaries (stippled) and venous capillaries (white) may be arranged in a rete mirahile. countered. \Ye have not done serial sections, and cannot say whether these pack- ing-patterns persist unchanged along the length of the rete. An important aspect of retial structure, which must he taken into account in formulating any theory of the action of the counter-current system is that the choroid rete is not uniform along the length of the capillaries. In longitudinal sections of the rete of all fish, but particularly conspicuous in the rete of larger fish such as tuna or opah (lampridae, Lainpris rcghis), the rete is seen clearly to he differentiated into proximal and distal portions of differing structure, with a sharp line of demarcation between them. This suggests that oxygen transfer by the choroid rete may be a two-stage process. The way in which the structures of the two parts of the rete differ is not easily resolved at the light microscope level. A study of the fine structure of the retial capillaries has been initiated in the labora- tory of Copeland (, Wolley and Copeland, 1970) and we await their resolution of this problem. We next describe the choroid rete mirabile of Ainia. The appearance of this rete, viewed from inside the orbit, is portrayed in Figure 6. The sclera, covering membranes and the ophthalmic venous sinus have been dissected away. As in teleosts, the ophthalmic artery divides into two main branches, which arborize over the surface of the rete. The elegant and ordered symmetry of the teleost rete is lacking, and. in contrast to the teleost pattern, the retial capillaries arise from stubby. 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 Marine
Size: 2033px × 1229px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
