RESUMO
Objective The filum terminale(FT)plays an important role in the pathophysiology of tethered cord syndrome(TCS).The study on morphology and structure of fetus FF can provide reference standard for diagnosis of TCS.Methods Ten fresh human aborted fetuses had their fila measured and removed.Transversal and longitudi nal sections of the middle,and distal thirds of FF were submitted to light microscopy analysis with four different techniques.Results The bulk of the Frr is composed of 1～5μm thick spring like longitudinal bundles of colla gen separated by 5～30μm layer intervals and 1～5μm intervals in the layer,although a small quantity of eapillar ies and other elements may be present.Collagen bundles can also be found between layers and bundles.Abundant longitudinally oriented elastic fibers ale found inside or between collagen bundles.Conclusion A complex tridi mensional structure composed by ordered arrangement of spring like fibers and small quantity of capillaries should e licit considerable elastic properties to the FI".Tts alternation of structure and element maybe involved in TCS closely.