Changes

Following neurulation, the precursor of the epidermis is formed from the cells covering the embryo.  This then becomes 2 layers, the outer forming the '''periderm''' and the inner forming the '''basal layer''' or ''stratum basale''.  A further layer is formed from the basal layer called the '''spinous layer''' or ''stratum spinosum''.  The basal and spinous layers are termed the ''Malphigian layer'', the cells of which then divide to produce the '''granular layer''' or ''stratum granulosum''.  As the cells of the granular layer differentiate and keratinise, they form the outer '''cornified layer''' or ''stratum corneum''.

Following neurulation, the precursor of the epidermis is formed from the cells covering the embryo.  This then becomes 2 layers, the outer forming the '''periderm''' and the inner forming the '''basal layer''' or ''stratum basale''.  A further layer is formed from the basal layer called the '''spinous layer''' or ''stratum spinosum''.  The basal and spinous layers are termed the ''Malphigian layer'', the cells of which then divide to produce the '''granular layer''' or ''stratum granulosum''.  As the cells of the granular layer differentiate and keratinise, they form the outer '''cornified layer''' or ''stratum corneum''.