barrier function
Maintain homeostasis
by constant recycling of the basal cell layer
Dermis
Fibroblasts
Constitutes the bulk of the skin
Composed of collagen with elastin
and glycosaminoglycans (GAG’s)
major role in the biomechanics of the skin
Hypodermis
Adipose tissue (vascularized, connective tissue)
Contributes to both the thermoregulatory
Shoo
■ Objectives of Defense-in-Depth
• To compensate for potential human and component
failures
• To maintain the effectiveness of the barriers by averting
damage to the facilities and to the barriers themselves
• To protect the public and the environment from harm in
the event that those barriers are not fully effective
■ Strategy of
Neurophysiological property
itch fiber
Histamine-sensitive
Low conduction velocity
Large innervation territories
Mechanical unresponsiveness
High electrical threshold
즉, itch fiber는
Histamine-positive mechano-insensitive
afferent C-fiber
diversity of cutaneous n.s.
Hypertrophy of nerve fiber
Enlarged axon
Axons lost their surrounding cytoplasm o
afferent C-fiber
diversity of cutaneous n.s
Hypertrophy of nerve fiber
Enlarged axon
Axons lost their surrounding cytoplasm of Schwann cells.
Immunological abnormality
T cell defect
CD8 suppressor/cytotoxic T cell↓
↑IL-4, ↓IFN-γ
Induce CD23(low-affinity IgER) on B cells
Increased IgE synthesis
Sustained T cell activation