Abstract
Human tendon was observed by scanning electron microscpy and the following conclusion was obtained.
1. Tendon surface presents wave structure and forms an arch and is arranged without adherence one another. At a higher magnification, it is oriented to a certain direction and a part of it is constituted from numberless collagen fibrils without direction.
2. Structure of the surface is different a little morphologically depending upon each tendon site. Comparsion of M. flexor digitorum profundus tendon and M. flexor digitorum superficialis tendon and tendon sheath at Noman's land shows rough structure and degenerated fibrils in collagen fibrils on surface of M. flexor digitoroum superficialis tendon of M. flexor digitorum profundus tendnon and the surface of M. flexor digitorum profundus tendon of M. flexor digitorum superficialis tendon.
In parietal layer of tendon sheath, arch meets at right angle with direction of tendon running. Extensor tendon presents flatter pictures than flexor tendon.
3. The vertical split surface of tendon is covered with endotendon, forming tendon bundles. The vertical split surface of the tendon bundle is composed of collagen fibrils runnig toward the long axis and lengthweise and crossweise fibrils connecting collagen fibrils.
4. At the muscle-tendon junction, tendon fibers and muscle fibers are running toward the direction of axis and muscle fibers and sarcolemma enter and connect into tendon fibers.
5. Tendon fibers running obliquely at the site of bone attachment go through periosteum, and enters into bone and branch finely and entangle with bone collagen fibrils in net state or without direction and transfer. Namely, fibrous connection of bone collagen fibrils and tendon fibers is supposed.
6. There is no formation of tendon bundle at the muscle tendon junction in transverse section of tendon, however, many areas which are considered to form tendon bundles are observed.
Formation of tendon bundles becomes apparent at the intermediate part and the tendon bundles are composed of collected bundle of numberless tendon fibers. The tendon bundle disappears again at the site of bone attachment and connects with bone fibers as each one of tendon fibers.
From above scanning electron microscopic observation, it is apparent that morphology of tendon surface has the structure effective for tendon lubrication by reducing friction surface and retention of synovialfluid as a lubrication and that tendon is the strong connective tissues which transmit contactile power of muscle to periphery.
