BIO 2135 Chapter Notes - Chapter DigiDiv: Pharyngeal Muscles, Nematomorpha, Hydrostatic Skeleton
24 Feb 2017
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Pseudocoelomate: body cavity that is not completely lined by mesoderm. Few morphological traits to distinguish one species from another physically all the species look the same. Collagenous cuticle: epidermis outer layer of the organism, made of cuticle, secreted by underlying. Meshwork organization of fibers within the cuticle, strengthens body wall against hydrostatic pressure cuticle can bend. Contraction of any muscle affects the entire length of the animal sinusoidal, whiplike movements. But it helps the animal move through the particles of dirt and sand. Nerve ring surrounding pharynx, connected to four or more nerve cords that run the length of the animal. Pharynx has triradiate arrangement of muscles, straight tube intestine (not lined with muscle), and anus. The presence of pores on the innermost ring of the papillae = chemosensory. Arrangement of the sensory papillae in two rings of six on the lips and an outer ring of small bumps on the surface of the cuticle four on the head.
