TY - JOURS
T1 - Die Evolution der Haut und des hautassoziierten Immunsystems 
Schempp, Christoph
JAS - Jahr für Goethe.
JF - Jahrbuch für Goetheanismus
PY - 2009
VL - 2009
SP - 21
EP - 82
DO - 10.18756/jfg.2009.21
SN - Print :1866-4830 Online : 2750-2341 
LA - de
N2 - 
N1 - The evolution of the skin and the skinassociated immune systemThis paper considers the formation of the skin and its associated structures from the most primitive metazoa to the human beingnbsp In Porifera the delirnitation from the outer world is incomplete A proper epidermal sheath does not exist merely a thin coating in the form of pinacoderm Dicotyledonous Cnidaria have an ectodermis and an entodermis both single layered which already show a certain functional specialisation The cells of the epidermis are fixed together with band desmosomes and ensure protection from the outer world Worms go through various metamorphoses of a still singlelayered epidermis which lead to a further intensification of the delimitation function formation of a syncytium neodermis of the Plathelminthes formation of a cuticle in Annelida and Nematoda The division of the organism into head thorax and abdomen as well as the formation of extremities in the Arthropoda is enabled by a hard exoskeleton in the form of a chitinised cuticlenbsp The Echinodermata the most primitive Deuterostomia exhibit a highly specialised but still singlelayered epidermisnbsp In the Tunicates the most primitive chordate animals the singlelayered epidermis is overlaid by tunicin a celluloselike substance produced by the dermal cellsnbsp The Cyclostomata the jawless fish are the first to form a multilayered epidermis This is pluripotent and impregnated with mucosal cells In the cartilaginous fish the multilayered epidermis maintains an exoskeletonlike supportive function through its many placoid scalesnbsp In the bony fish these recede into the background in the form of elastic dermal scalesnbsp With the amphibians the transition from life in water to life on land leads to the first cornification of the outer cell layer of the epidermis But the amphibians still remain connected with an aquatic environmentnbsp Only with the reptiles and the development of an amnion is a complete separation from the aquatic environment achieved A stroneg marked cornification of the epidermis is often associated with this the cornified layer has to be shed as a wholenbsp In birds the denizens of the air the epidermis forms a novel coating of various kinds of feathers As with the feather spines some of the bones are filled with air The feathers significantly contribute to the maintenance of the as yet incomplete homeotherrnynbsp In mammals a further novel formation of the epidermis is hair which regresses only in the human being and secondary aquatic mammalsIn parallel with the increasing delimitation of the organism from the outer world by means of the skin an innate immune system first of all developed on the basis of phagocytes and unspecific yet highly effective humoural defence factors The first demonstrable adaptive immune system came with the cartilaginous fish The development and compartmentalisation of the lymphatic system brought the formation of an immune system associated with the skin which in mammals especially the human being spatially comprises three components At the skins outermost barrier to the outside world a cellular more sensory expression of the immune system predominates In the middle layers of the dermis the dominant component is a dense network of capillaries which mediates the circulation and migration of immune cells In the deeper layers of the skin proliferative processes predominate Thus the subcutis and its lymph nodes associated with the skin belong to the metabolic pole the reticular dermis to the circulatory system and the epidermis to the nervesense system
AB - 
ST - Die Evolution der Haut und des hautassoziierten Immunsystems 
UR - https://dx.doi.org/10.18756/jfg.2009.21
Y2 - 2024-05-17 01:42:54
ER -