Histological and histochemical studies on the small and large intestine of chickens of different age groups
Abstract
The broiler chicken of 07, 14, 21, 28, 35 and 42 days age group were used to collect intestines
for the present study. The tissues were collected from duodenum, jejunum, ileum, caecum, colon,
cloaca along with their respective junctions for histological and histochemical studies on the small and
large intestine. Histologically, the wall of small and large intestine was having four tunics i.e. tunica
mucosa, tunica submucosa, tunica muscularis and tunica serosa. The villi were present throughout in
small and large intestine. The villi of various shapes and size were present and these were lined by
simple columnar epithelium having chief, goblet, and endocrine cells. The goblet cells were increased
from duodenum to cloaca whereas endocrine cells decreased from duodenum to jejunum and increased
from ileum to cloaca. At caecal tonsil region epithelium towards the base of the villi facing the fossulae
was modified in to the follicle associated epithelium (FAE), This FAE at certain positions presented the
cells which resembled the M-cells. The lamina propria was having irregular connective tissue with
densely packed connective tissue cells in the core of the villi. Fine blood capillaries were oriented
parallel to the longitudinal axis of villi. At the bases of the villi, intestinal glands or crypts of
Lieberkuhn were present. Only isolated collagen fibres were present and the reticular fibres formed the
basement membrane and surrounded the periphery of intestinal glands. Histochemically, the goblet
cells of surface epithelium and glands showed different affinities for acidic mucopolysaccharides,
mucins, glycogen, weakly sulfated acidic mucopolysaccharides, hyaluronic acid and sialomucins
however, the neutral mucopolysaccharides were present in negligible amount. Lamina muscularis
mucosae and submucosa was not well-developed whereas, at few places, it appeared wider. At 21-days
of duodenal-gizzard junction Brunner’s glands were observed. Tunica muscularis was consisted of
inner circular and outer longitudinal layer of smooth muscle fibres. Tunica serosa was having loose
irregular connective tissue, fine blood capillaries and isolated nerve bundles followed by flat
mesothelial cell layer. Generally the constituents of different layers of small and large intestine
presented developmental changes with the advancement of age.
Description
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