INTRODUCTORY-NEMOTOLOGY (original) (raw)
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2013
The cuticle of Haemonchus contortus has on its outer surface a highly resistant epicuticleexocortex complex possessing a substantial amount of acid mucopolysaccharides in the epicuticle and lipid in the outer cortical layer forming a permeability barrier. The longitudinal ridges found in both the sexes, pertaining to the anterior region of the body, are supported by tough resistant struts. The median layer of the cuticle from where these struts arise is well developed, whereas the basal layer is less developed and its striated nature is also not evident. Histochemically, the carbohydrates and lipids are found in high quantities in the cuticle in general. The protein is restricted to the outer cortical and median layers only. The hypodermal areas are positive for lipids and carbohydrates. Large amount of glycogen is present in the non-contractile part the muscle cells except the perinuclear spaces whereas the contractile portion contains large concentration of proteins. However, both these areas of muscle cells are negative for nucleic acid activity.
Lecturer 01: Introduction, History and Taxonomy of Plant Parasitic Nematodes
Nematology Nematology is the scientific discipline that deals with the study of nematodes. Nematology is conventionally concerned with the study of phyto-nematodes which parasitize plants and are of economic importance to agriculture, horticulture and forestry. "Nematode" is a greek word (nema = thread, oides = form) i.e. thread like organisms as they look like tiny threads moving under microscope. Nematodes Nematodes may be defined as bilaterally symmetrical, triploblastic, pseudocoelomic, unsegmented invertebrates with four hypodermal chords, a tri-radiate oesophagus, circum oesophageal nerve ring and a definite tail but lack circulatory muscles and specialized organs for locomotion and respiration. Nematodes belong to phylum Nematoda (also called Nemathelminthes). Synonyms: Threadworms, eelworms (serpentile eel like body), round worms, nemas, paudh/padap, krimi etc.
The Structure and Chemical Composition of the Body Wall of Animal-Parasitic Nematodes
2018
The nematode body is enclosed by a body wall comprising of three different layers. The outermost being a thick multilayered cuticle underlined by the middle hypodermal layer pronounced at four regions in the form of dorsal, ventral and a pair of lateral hypodermal cords. The innermost layer is constituted by a single layer of longitudinal muscle cells. Although the outer envelope of nematodes has been studied by a host of workers yet the controversy regarding certain aspects of its structure, chemical composition and function still prevail. The presence of proteins, carbohydrates, lipids, acid mucopolysaccharides and a variety of enzymes have been detected by various workers in different species of larval and adult nematodes. Since the mere survival of a nematode parasite in the body of its host is mainly attributed to the uniqueness of its body covering, hence the study of its nature and chemical composition is of paramount importance in parasitic nematology. The present paper brie...