Tympanic part of the temporal bone presents a narrow furrow, the "tympanic sulcus", for the attachment of the tympanic membrane. Its antero-inferior surface is quadrilateral and slightly concave; it constitutes the posterior boundary of the mandibular fossa, and is in contact with the retromandibular part of the parotid gland. Its lateral border is free and rough, and gives attachment to the cartilaginous part of the ear canal. Internally, the tympanic part is fused with the petrous portion, and appears in the retreating angle between it and the squama, where it lies below and lateral to the orifice of the auditory tube. Posteriorly, it blends with the
Eggshell membrane membrane is derived commercially from the eggshells of industrial egg processors. In the United States, egg-breaking facilities generate more than 24 billion broken eggshells every year. There are various ways in which the membrane of an eggshell is separated from the shell, including chemical, mechanical, steam, and vacuum processes: see Eggshell and protein membrane separation. It may be prepared for use as a dietary supplement. The isolated membrane is partially hydrolyzed and dried to produce a powder, that is distributed as eggshell membrane (EM) for use as a dietary supplement. Eggshell membrane Eggshell membrane or shell membrane is the clear