The cochlea is a three-chambered fluid-filled spiral tube

Evidence

The cochlea consists of a tube coiled into a spiral with approximately 2.75 turns—see Figure 2.3(a). The end with the oval and round windows is the “base” and the other end is the “apex”—see Figure 2.3(b). Figure 2.3(c) illustrates the effect of slicing through the spiral vertically, and it can be seen in (d) that the tube is divided into three sections by Reissner’s mem­ brane and the basilar membrane. The outer channels—the scala ves­ tibuli (V) and scala tympani (T)—are filled with an incompressible fluid known as “perilymph,” and the inner channel is the scala media (M). The scala vestibuli terminates at the oval window and the scala tympani at the round window. — David Howard, Jamie Angus, coustics and Psychoacoustics, 543

The cochlea consists of a tube coiled into a spiral with approximately 2.75 turns— see Figure 2.3(a). The end with the oval and round windows is the “base,” and the other end is the “apex”—see Figure 2.3(b). Figure 2.3(c) illustrates the effect of slicing through the spiral vertically, and it can be seen in 2.3(d) that the tube is divided into three sections by Reissner’s membrane and the basilar membrane. The outer channels—the scala vestibuli (V) and scala tympani (T)—are filled with an incompressible fluid known as perilymph, and the inner channel is the scala media (M). The scala vestibuli terminates at the oval window and the scala tympani at the round window. An idealized unrolled cochlea is shown in Figure 2.3(b). There is a small hole at the apex known as the “helicotrema” through which the perilymph fluid can flow. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 544

Categorization

• DEFINE: Core anatomy: coils, base/apex, perilymph-filled scala vestibuli and tympani separated by Reissner’s and basilar membranes.
• corroborated: 3 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 543; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 544
• XREF: connects to: The cochlea is a 2.75-turn spiral tube with a leak at its apex; Incompressible cochlear fluid makes oval and round windows move in opposite phase; Cochlear hydromechanics can be approximated by one-dimensional lumped sections. (+2 more)

Broader Connections

• The cochlea is a 2.75-turn spiral tube with a leak at its apex #qualifies (0.95)
• The ossicles convert air vibrations into mechanical movements that drive cochlear fluid #expands (0.80)
• Incompressible cochlear fluid makes oval and round windows move in opposite phase #expands (0.75)
• Cochlear hydromechanics can be approximated by one-dimensional lumped sections. #expands (0.75)
• The basilar membrane’s mechanics enable the inner ear’s frequency analysis #expands (0.70) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 547