Figure 3: Effect of TFHL on ultrastructural changes of the injured spinal cord. The changes in ultrastructure of spinal cord tissues were observed by transmission electron microscopy in each group (n = 3; cross-section of the T10 segment of the spinal cord; scale bars: 2 μm for the sham operation group and 1 μm for other four groups). In the sham operation group, the shape and structure of the myelin sheath were regular, the nerve cell nucleus was large and round, and the mitochondria were full. In the spinal cord injury (SCI) group, the shape and arrangement of the myelin sheath were irregular and disordered; the slab structure was loosely arranged, broken, and twisted; the mitochondria were swollen; and the nerve cell nucleus was irregular. In the SCI + TFHL groups, the conditions improved with drug concentration. In particular, the SCI + 20 mg/kg TFHL group demonstrated an obvious effect. Arrows indicate the myelin sheath and nerve cell nucleus of spinal cord tissue. SCI: Spinal cord injury; TFHL: total flavonoids of hawthorn leaves.