Cochlea Arises From

The cochlea is a spiral-shaped, fluid-filled structure in the inner ear that is responsible for hearing. It is a complex structure that arises from several different tissues during embryonic development.

Embryonic Development of Cochlea

During embryonic development, the cochlea arises from several different tissues, including:

1. Otocyst: The otocyst is a hollow ball of cells that forms during early embryonic development. It gives rise to the inner ear, including the cochlea.

2. Endolymphatic duct: The endolymphatic duct is a tubular structure that connects the otocyst to the endolymphatic sac. It is responsible for the production and regulation of endolymph, the fluid that fills the inner ear.

3. Mesenchyme: Mesenchyme is a type of embryonic connective tissue that gives rise to many different structures in the body, including the bones of the skull and the cartilage of the ear.

4. Neuroepithelium: Neuroepithelium is a type of embryonic tissue that gives rise to the cells of the nervous system, including the sensory cells of the inner ear.

Formation of Cochlea

The cochlea forms through a process called morphogenesis, which involves the shaping and differentiation of the embryonic tissues. During morphogenesis, the otocyst undergoes a series of complex changes that give rise to the three main compartments of the cochlea:

1. Scala vestibuli: The scala vestibuli is the upper chamber of the cochlea. It is filled with perilymph, a fluid that surrounds the inner ear.

2. Scala media: The scala media is the middle chamber of the cochlea. It contains endolymph and is separated from the scala vestibuli by the vestibular membrane and from the scala tympani by the basilar membrane.

3. Scala tympani: The scala tympani is the lower chamber of the cochlea. It is also filled with perilymph and is separated from the scala media by the basilar membrane.

Conclusion

In conclusion, the cochlea arises from several different tissues during embryonic development, including the otocyst, endolymphatic duct, mesenchyme, and neuroepithelium. These tissues give rise to the complex structure of the cochlea, which is responsible for hearing.