Histological structure of the nasal cartilages and their perichondrial envelope. II. The perichondrial envelope of the septal and lobular cartilage.

The perichondrial envelopes of the septal cartilage and the lateral crus of the lobular cartilage were studied in serial coronal sections of five human noses. To differentiate between the various tissue components, the sections were stained according to Mallory-Cason, Azan, Herovici, Verhoeff-van Gieson, and Lawson. Collagen types I and II were immunohistochemically stained. The results demonstrated that the perichondrium of the septal cartilage and the lateral crus of the lobular cartilage consists of a homogeneous layer of type I collagen fibers and elastic fibers. The elastic fibers have a network-like arrangement and are most numerous in the perichondrium of the lateral crus of the lobular cartilage. Clearly distinguishable zones in the perichondrial envelopes could not be observed. The perichondrium on the outside of the lateral crus of the lobular cartilage and the triangular cartilage is significantly thicker than the inner perichondrium. It is speculated that these morphological characteristics of the perichondrial envelopes are related to functional differences between the cartilages. The mobility of the lateral crus of the lobular cartilage requires a higher content of elastic fibers in its perichondrium than the more rigid septal cartilage. A thicker outer perichondrium of the lateral crus of the lobular cartilage and the triangular cartilage may be related to muscular forces that are exerted on the outer side of the cartilages only.