Most auditory nerve fibers carry messages hair cells.

Most auditory nerve fibers carry messages from the inner hair cells.

Explanation:

The internal hair cells group the frequency and intensity of the sound stimulation, which is then transmitted to the brain by the auditory nerve fibers. Frequency coding in mammals is associated with cochlear tonotopia. However, the sounds of frequency lower than 3 kHz, their coding is based on phase blockage at the level of hair cells.

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the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.