Avian cecal microanatomy: A morphometric comparison of two species

Abstract

Tissues from the proximal, middle, and distal regions of the ceca of Gambel's quail and domestic fowl were examined by scanning and transmission electron microscopy for ultrastructural detail. Cellular aad subcellular structures, including epithelial cell height, mitochondrial volume fraction, microvillar surface area, and junctional complex characteristics, were quantified by stereologic procedures. The mucosal surface of the quail ceca shows a more highly developed pattern of ridges and flat areas than that of the fowl. The fowl has significantly greater cell heights than the quail in all cecal regions. The mitochondrial volume fraction does not differ significantly with species or region, but the mitochondria in all samples tend to be concentrated on the apical side of the nucleus. In both species, the proximal cecal region has the greatest microvillar surface area. In the fowl cecum, the zona occludens and macula adherans heights are significantly less in the proximal than in the middle or distal regions. In the quail cecum, the zona adherans height is least is the distal region. The zona occludens height in the fowl middle and distal regions is significantly greater than those for the quail. The middle region of the quail cecum has the lowest proportions of cell boundaries with zona adherans and macula adherans in the junctional complexes. When all factors are considered, the quail ceca appear to have morphological characteristics consistent with a greater potential capacity for absorption by passive diffusion than the fowl ceca.The gross anatomy, including form, function, and occurrence, of the avian cecum has been well covered by McLelland (this issue) and others in the older literature (Leopold, '53; Ziswiler and Farner, '72; Duke, '86). However, relatively little work has been done on the ultrastructure of avian ceca. Hodges ('74) described the various layers in the walls of the ceca of the domestic fowl (Gallus domesticus), including muscularis externa, submucosa, muscularis mucosae, and mucous membrane, and he discussed three distinct regions of the ceca. The proximal region had well developed villi, with lymphoid cells in the tunica propria and many goblet cells in the epithelium. In the middle region, cecal walls were thinner than in the proximal region, and well developed longitudinal folds were present in the mucous membrane. In the distal region, the folds were less developed, and the villi were short and blunt. The proportion of goblet cells decreased from the proximal to the distal region. Clarke ('78) examined the ileocecorectal junction in the domestic fowl and found a muscular ring of tissue projecting into the lumen of the intestine immediately anterior to the cecal openings. These openings were narrow and filled with villi. Clarke suggested 0 1989 ALAN R. LISS, INC.that this structure could be related to filtering of material during filling of the ceca. Hanssen ('79) qualitatively described the microanatomy of the ceca and small intestine of wild and captive willow grouse (Lagopus l...

Morphological Characteristics of the Developing Cecum of Japanese Quail (Coturnix coturnix japonica)

“…Through the embryonic stages, middle and distal parts were provided with short and few microvilli. This finding was similar to that reported by Strong et al (1989) in both quail and fowl where the short and stubby microvilli were found in the distal part. Abd El-Wahab et al (2017) reported a decrease in length of epithelial microvilli from distal, middle to proximal parts of ceca of common quail, Muscovy duck, and little owl.…”

“…Abd El-Wahab et al (2017) reported a decrease in length of epithelial microvilli from distal, middle to proximal parts of ceca of common quail, Muscovy duck, and little owl. The surface area increase due to microvilli could be related to both active and passive transcellular transport with greater surface areas permitting more absorption of the materials from the cecal lumen (Strong et al, 1989). Considering that the microvilli are associated with a number of hydrolytic enzymes, they might affect the terminal hydrolysis of peptides and disaccharides (Ugalov, 1966; Johnson, 1967).…”

Histology and ultrastructure of the gastrointestinal tract in four temperate marine herbivorous fishes

“…In many vertebrates, the absorptive region of the GIT is increased by folding of the intestinal mucosa, villi and microvilli (e.g., German et al, 2010;Langer & Takács, 2004;Strong et al, 1989). These structures can act to slow the rate of passage (Stevens & Hume, 1995), and may enable the retention of material in certain regions of the gut (Clauss et al, 2004;Langer & Takács, 2004) thus increasing the time for nutrients derived from ingesta to be assimilated.…”

“…It would therefore be advantageous for hindgut fermenters to have greater surface area in the hindgut, as this could enable retention of digesta due to folds in the intestinal mucosa and could facilitate more efficient uptake of short-chain fatty acids (SCFA) made available via endosymbionts (Stevens & Hume, 1995). Increasing the surface area of the GIT potentially enables more rapid absorption of nutrients from the lumen relative to a GIT lacking folds or villi, as suggested in studies on the fermentation regions of avian species (Strong et al, 1989).…”

Bıldırcın (Coturnix Coturnix Japonica) Sekumunda Mast Hücrelerinin Dağılımı ve Heterojenitesi

“…It comprises three parts, the proximal, middle and distal [3] , and plays a role in various functions, including the digestion and fermentation of cellulose and the absorption of water, sodium, carbon dioxide [4] and nutrients [2] . Additionally, it contains diffuse and nodular lymphatic tissues in its submucosa and lamina propria.…”