Decalcified bone with Haversian system cut longitudinally. Notice the central blood vessel and the many concentric bony lamellae around it. As always, osteocytes are trapped in their lacunae.

• 脱钙骨片切片，示哈佛氏系统的纵切面。观察中央管内有血管走行，中央管周围，有多层骨板相环绕。骨细胞位于骨陷窝中。