. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NEPHRIDIUM OF THE MITRARIA LARVA 317 nc es. 100pm FIGURE 1. Diagram of the mitraria larva of Owenia fusiformis (after Wilson, 1932). an, anus; br, cerebral ganglion; cb. prototrochal ciliary band; em, esophageal muscle; ep, episphere; es, esophagus; hp, hyposphere; in, intestine; 1m, dorsal levator muscles; mo, mouth; nc, circumesophageal nerve cord; nd, nephridioduct; ne, nephridium; ss, setal sac; st, stomach; tr, trunk rudiment. Transmission electron microscopic observations indicate that each nephridial sac is lined by m
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NEPHRIDIUM OF THE MITRARIA LARVA 317 nc es. 100pm FIGURE 1. Diagram of the mitraria larva of Owenia fusiformis (after Wilson, 1932). an, anus; br, cerebral ganglion; cb. prototrochal ciliary band; em, esophageal muscle; ep, episphere; es, esophagus; hp, hyposphere; in, intestine; 1m, dorsal levator muscles; mo, mouth; nc, circumesophageal nerve cord; nd, nephridioduct; ne, nephridium; ss, setal sac; st, stomach; tr, trunk rudiment. Transmission electron microscopic observations indicate that each nephridial sac is lined by monociliated podocytes which lie on a basal extracellular matrix (ECM), averaging 90 nm in thickness (Figs. 2B-D; 3A). At the point of origin of the dorsal levator muscles from the nephridium, the nephridial lumen is lined by both podo- cytes and myocytes which are continuous with the levator muscle (Fig. 2B). There- fore, the levator muscle is a modified part of the nephridial lining as is the levator muscle in the tornaria larvae of hemichordates (Morgan, 1894; Ruppert and Balser, 1986). Each podocyte consists of a cuboidal perikaryon, ^m high, which bulges into the nephridial cavity (Fig. 2B-D), and attenuated, lateral foot processes (pedicels). Filtration slits between adjacent pedicels are 40-70 nm in diameter and lack diaphragms (Fig. 2D). Adhaerens junctions join the lateral surfaces of adjacent podocytes (Fig. 2E inset). The luminal surface of each perikaryon bears a single cilium and filiform microvilli. The cilium, which is oriented towards the duct, arises from a. 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 Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richar
Size: 1263px × 1979px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
