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Microscopic Pathology:
Adult tendons are composed of large-diameter type I collagen fibrils. These are 150 nm in diameter, tightly packed with type III collagen, and dispersed in an aqueous gel containing proteoglycan and elastic fibers (Harries, 1998). The actin and myosin bundles are arranged helically. In healthy tendons, 95% of the collagen is type I (Maffulli, 2000 Jul-Aug). Degenerate tendons have less type I collagen and significantly more type III collagen. The same changes are also seen during the natural aging process, although to a lesser extent. This may be why the tendon is less elastic in older individuals and more prone to rupture (Jozsa, 1984).
Type III collagen seems to be the major collagen synthesized in the healing tendon after injury. This observation again suggests that the tendon degeneration in tendinosis is an incomplete repair process.
Animal testing has shown that tendons can stretch by 4% of their original length before damage occurs. If stretched more than 8%, rupture is likely (Whittaker, 1991).
Plant Pathology :
Plant pathology (also called phytopathology) is the scientific study of plant diseases caused by pathogens (infectious diseases) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are insects, mites, vertebrate or other pests that affect plant health by consumption of plant tissues. Plant pathology also involves the study of the identification, etiology, disease cycle, economic impact, epidemiology, how plant diseases affect humans and animals, pathosystem genetics and management of plant diseases.
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