Tuba section in a British style brass band. Tubas are found in various pitches, most commonly in F, E â­ , C, or B â­ . The main tube of a B â­ tuba is approximately 18 feet (5.5 m) long, while that of a C tuba is 16 feet (4.9 m), of an E â­ tuba 13 feet (4.0 m), and of an F tuba 12 feet (3.7 m). The instrument has a conical bore, meaning the bore diameter increases as a function of the tubing length from the mouthpiece to the bell.
The total body water is divided into intracellular and extracellular fluids. Plasma is considered __.
The gastro-intestinal tract of mammals consists of four main layers, the mucosa, submucosa, muscularis and serosa. The innermost of these layers, the mucosa can be divided into the epithelium, lamina propria, and muscularis mucosa. The epithelial lining may be protective, secretory, and/or absorptive in function.