What fluid is primarily involved in the transmission of sound waves in the cochlea?

The fluid that is primarily involved in the transmission of sound waves in the cochlea is perilymph. Within the cochlea, sound waves enter through the oval window, which transmits vibrations to the fluid-filled spaces of the cochlea. Perilymph is located in the scala vestibuli and scala tympani, two of the three fluid-filled chambers of the cochlea.

The properties of perilymph allow it to effectively conduct sound waves. It has a composition and density suitable for transferring mechanical vibrations initiated by sound waves, allowing them to stimulate the hair cells located in the organ of Corti. These hair cells then convert the mechanical vibrations into electrical signals that the auditory nerve transmits to the brain, enabling the perception of sound.

In contrast, cerebrospinal fluid is primarily involved in cushioning and protecting the brain and spinal cord rather than sound transmission. Lymph fluid is part of the lymphatic system, playing roles in immune function and fluid balance, and is not involved in auditory processes. Semen is a reproductive fluid containing sperm and is not related to sound transmission in the cochlea. Thus, perilymph's role and properties make it essential for the transmission of sound waves within the cochlea.