Testicular Artery

Vertical section through the testicular artery, which is a muscular-type artery . The tunica interna or tunica intima is the innermost layer in this vessel. Its outer luminal layer of endothelial cells 1 protects against the forces of the bloodstream. Nuclei of endothelial cells are not capture d in this section and cytoplasmic structural elements are not recognizable at this magnification.  The layer underneath the endothelium is the very thin lamina propriaintima .  It contains collagen fibrils. The following internal elastic membrane 2 is clearly defined. In this area, the tunica me dia consists of four muscle cells 3 with mostly contractile filaments. The nucleus of the muscle cell underneath the elastic internal membrane is visible. There are numerous small mitochondria in the perinuclear space. Collagen fibrils are intersperse d with myocytes of the tunica me dia. A thin external elastic membrane 4 separates the tunica media and tunica adventitia 5 .

1 Endothelium

2 Internal elastic membrane

3 Tunica media myocytes

4 External elastic membrane

5 Tunica adventitia

Electron microscopy; magnification: × 4000

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 .