Mastoid cells are air spaces lined with mucous membrane and opening into the tympanic cavity. As part of the chain of auditory (Eustachian) tubes, mastoid cells constitute the last one. In children, the mastoid auricular bone is absent - cartilage does not form into it, but ossification does occur. It is also impossible not to say that it is the most developed in the skull, and contains parts of the brain or paranasal sinuses. The latter is called the pneumatic appendage. Clinically, the mastoid process is defined as a painless, palpable formation located in the temporal region. In itself, the presence of such a process in a person does not have any effect on his life. However, when it undergoes surgical treatment, a person loses the ability to distinguish high-frequency sounds for quite a long time. It is especially difficult for those who wear glasses - this is already aggravated by vision problems. The presence of a mastoid fossa on the skull is explained by the fact that in the process of evolution it turned from a gill arch.