• Title/Summary/Keyword: Chelicera

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Fine Structural Analysis of the Venom Apparatus in the Spider Araneus ventricosus (산왕거미 (Araneus ventricosus) 독 생성장치의 미세구조 분석)

  • Moon, Myung-Jin;Yu, Min-Hee
    • Applied Microscopy
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    • v.37 no.2
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    • pp.53-63
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    • 2007
  • The culticular substructure of the venom apparatus in the orb-web spider Araneus ventricosus are studied with scanning electron microscopy. The apparatus is composed of chelicera and paired venom glands in the cephalothorax. Each chelicera consists of a basal segment and a movable fang that articulates with each other. The chelicera of this spider is labidognathous form that moves at right angles to the body axis, and has two segments similar to that of a folding jackknife. Each cylindrical fang has a specialized hinge joint which articulate with the cheliceral groove which contains numerous small protrusions. In addition, each side of cheliceral groove is covered with a total of 7 cuticular teeth in two rows which composed of 4 promarginal and 3 retromarginal teeth. It has been also observed that a single venom pore is always located toward the direction of retromarginal teeth, and surface cuticular pits are distributed on the cuticular depressive area of cheliceral groove.

Ultrastructural Study on the Poison Secreting Organ of the Spider (거미류 독액(毒液) 분필기관(分泌器官)의 미세구조(微細構造)에 관한 연구(硏究))

  • Moon, Myung-Jin
    • Applied Microscopy
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    • v.22 no.1
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    • pp.128-142
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    • 1992
  • Ultrastructure of the poison secreting organ in the spiders, Agelena limbata Thorell and Nephila clavata L. Koch were studied using scanning and transmission electron microscopes. The venom glands located its secretory sac portion in cephalothorax and excretory duct in the fang of chelicera are one pair of simple alveolar glands composed of three kinds of basic tissues-outer spiral musculature, middle myoepithelium and inner glandular epithelium. The muscle cells of the venom gland junctioned with the motor nerve endings at neuromuscular contact area are composed of smooth muscle fibers, whereas the myoepithelial cells between the musculature and inner glandular epithelium have compact collagenous fibers within the cytoplasm. The glandular epithelial cells which arranged along the concentrical location are subdivided into basal light cells and apical dark cells according to electron densities of their cytoplasms.

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Fine Structural Aspects of the Venom Production in the Black Widow Spider, Latrodectus mactans (검은과부거미 (Latrodectus mactans) 독 생성과정의 미세구조)

  • Moon, Myung-Jin;Tillinghast, Edward K.
    • Applied Microscopy
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    • v.26 no.1
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    • pp.17-31
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    • 1996
  • The venomous apparatus of the black widow spider, Latrodectus mactans, is composed of chelicera and paired venom glands in the cephalothorax. Each glands is surrounded by a thin adventitia and striated muscular bundles resting on a basal membrane. Along the musculature neuromuscular synaptic contacts are formed by a motor axon and the muscle fibers. The secretory epithelium, which made up of simple and long columnar cells with extensive finger-like processes, creates a simple acinar gland. The secretory surfac is increased by a sort of fringes extended from the basal membrane into the gland lumen, and the luminal surface of the epithelium is marked by the presence of closely spaced microvilli. The venoms of the black widow spider are produced from two types of secretory granules within the epithelial cells. During the secretory phase, these granules are transformed into droplets and suffering a condensation. Finally the secretory products are released by the apocrine secretion. After the gland is emptied, the basal epithelial cells present a high proliferative process and regenerate the columnar epithlial cells.

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