横切面上，主段二联微管A管上的动力臂明显，两条中央微管间有短的横桥连接，中央微管通过放射状辐与二联微管A管相连。
On the transection of principal piece , two dynein arms attached to a microtubule of the doublet which connected with the central microtubules through an obvious radial spoke . Two central microtubules are linked by a bridging substance .
二联微管