The inner ear is a bony chamber filled with fluid. It houses the semicircular canals and the cochlea. The semicircular are responsible for sense of balance and detection of body movement. The cochlea is a spirally coiled tube of three chambers and resembles a snail shell (Figure 5.11). One chamber (scala vestibuli) begins at the oval window and another chamber (scala tympanic) starts at the round window. The two chambers join at the tip of the spiral, called the helicotrema. A third chamber (scala media) separates the first two chambers (Figure 5.12).