Tympanic membrane retraction adherent to other structures within the middle ear. Some retractions continue to progress and grow more deeply into the ear. This can result in erosion of bone. As the middle ear is only a narrow space, the eardrum only has to retract a short distance before it touches boney structures within the middle ear such as the ossicles. It may become adherent to these bones and in some cases, this contact leads to erosion of the bone. As well as ossicular erosion, the bone of the ear canal (e.g. the scutum) and even bone over the cochlea (the promontory) can
Plasma membrane transformation they do in rats and mice, after which they return (within the next 48 h) to form the interface of the mature placenta. Moreover, as we have also seen, there are molecular alterations in the plasma membrane during early pregnancy which have common aspects across species and here some of the large mucin molecules (such as MUC-1) are particularly instructive. Changes in the basal and lateral plasma membrane regions have also been documented in many species during early pregnancy in preparation for attachment, and these too show common aspects across species—especially some membrane junctional structures. Therefore, to highlight that membrane