Constricting Artery-Special Type of Artery

Close to branching points in the arterial circulatory system, there are often prominences in the shapes of walls, lips or beaks. These arterial prominences  or cushions may play a role in the fine-tuning of the blood distribution. The  figure shows a muscular prominence 1 in an artery of the psoas muscle. It has caused the endothelium 2 to protrude quite far into the arterial lumen.  An elongated nucleus from a muscle cell 3 is visible in the lower part of the photograph. Note the filament system of the contractile myocyte , followed by thin processes from fibrocytes along with collagen fibrils.

1 Muscular prominence

2 Endothelium

3 Myocyte

4 Connective tissue

Electron microscopy; magnification: × 7500

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgart · New York .