Page 96 - Veterinary Histology of Domestic Mammals and Birds, 5th Edition

78 Veterinary Histology of Domestic Mammals and Birds

cells may be present within the same lacuna (isogenous
VetBooks.ir cell group). Mitosis is an indicator of interstitial cartilage
growth. Mature cartilage is capable of only limited regen-
eration, with fibrous scar tissue occurring in its place.
The collagen fibres in hyaline cartilage are arranged
along lines of mechanical pressure and tension. At the sur-
face, the fibres are curved to form arcades, from which they
transition into a more oblique orientation (Figure 3.24).
The fibres within the cartilage are in contact with fibre
bundles in the perichondrium. This arrangement results
in even distribution of mechanical stresses across multiple
chondrons. The type II collagen fibres cannot be identi-
fied under standard light microscopy, as these are masked
by the homogeneous glassy (hyaline) matrix in which they
are embedded. They can be identified using biochemical and
3.25 Elastic cartilage (schematic). The network of elas- immunocytochemical techniques, and with electron micros-
tic fibres exhibits extensive branching. copy. Under polarised light they are uniaxially birefringent.

Interterritorial matrix

Chondrocyte with capsule

Isogenous cell group within a common lacuna

3.26 Features of hyaline cartilage include isogenous cell groups (formed primarily by superficial chondrocytes)
and pale-staining, homogeneous interterritorial matrix. Collagen fibres are not discernible. The chondrocytes
lie in lacunae. As a result of tissue preparation, the cells exhibit a varying degree of shrinkage. Hyaline cartilage
of the third eyelid, horse. Haematoxylin and eosin stain (x480).

Chondrocytes

Elastic fibre network

Interterritorial matrix
3.27 Epiglottis (dog). Elastic cartilage fea-
tures a dense network of dark red-staining
elastic fibres and paler ground substance.
Chondrocytes are located between the
branching fibres. Orcein-haemalaun stain
(x480).

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