pepsinogen. a zymogen secreted by the chief cells of the gastric glands and converted into pepsin in the presence of gastric acid or of pepsin itself.plasma pepsinogen. high levels are indicative of extensive mucosal damage in the abomasum, as in ostertagiasis in ruminants. proenzyme formed and secreted by the chief cells of the gastric mucosa; the acidity of the gastric juice and pepsin itself remove 42 amino acid residues from pepsinogen to form active pepsin. Synonym(s): propepsin. [ pepsin + G. -gen, producing].
Princeton's WordNet(5.00 / 1 vote)Rate this definition: 1  reed(noun) tall woody perennial grasses with hollow slender stems especially of the genera Arundo and Phragmites.
How Woodwind Instruments Work. Woodwinds are one of the major families of instruments in use today. Woodwinds are basically defined as hollow tubes, which, when blown on one end, produce a sound. Most wind instruments have keys or fingerholes to vary the pitch of the sound, and different methods may be used to create the basic sound. Mouthpieces Single Reed (Clarinet/Saxophone) The single reed produces a sound by vibrating against the mouthpeice when blown. The reed is held down by a metal ligature. Reeds are very sensitive, and must be cared for to produce the right tone. Double Reed (Oboe/Bassoon) The double reed uses two reeds, tied together, to make a sound. The sound it produces is somewhat nasal, and can be very difficult to build, maintain, and play. Most double reed players make their own reeds. The tight opening of the double reed means that the musician can play long phrases in one breath.