الفهرس 
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Abstract
The present work was carried out on eighty five female geese at
three different stages of development: immature, sexually mature, and
egg laying period. Immediately after the geese were humanly scarified
and eviscerated, pieces of the left oviduct were taken, fixed in 10%
buffered neutral formalin and processed until paraffin sections were
prepared for the light microscopic study. In addition, pieces of the left
oviduct were fixed, in 2.5 % glutaraldehyde and processed until ultra-thin
sections were prepared for transmission E/M examination.
The term oviduct in the geese is used to describe the entire
reproductive duct. Only the left oviduct is present in the adult bird. The
development of the right oviduct of female geese is totally arrested very
early in embryonic life. The left oviduct, anatomically speaking, is
divided into infundibulum, magnum, isthmus, uterus and vagina, each of
these anatomical divisions has special structural and functional features.
Microscopically, the oviduct has the characteristics of a tubular organ,
whose wall is formed of tunica mucosa, submucosa, muscularis and
serosa or adventitia in the most caudal part of the oviduct.
The oviduct of immature birds is simple in structure, and its wall is
formed of tunica mucosa, submucosa, muscularis and serosa. The tunica
mucosa shows longitudinal folds which, appears in cross section as short
primary folds. In immature geese, the covering epithelium of the mucosal
folds is a simple epithelium, and is formed of light and dark cells, which
are columnar in shape. However, the dark cells are the predominant types
and exhibit rod-shaped darkly stained nucleus, and acidophilic cytoplasm.
On the other hand, the light cells are fewer in number and exhibit oval
vesicular nucleus near their base. The propria-submucosa is highly
cellular; its vascular connective tissue contains lymphocytes and
fibroblasts.
The lamina propria exhibits a collection of small lymphocytes
(lymphoid follicles), -and blood vessels. The tunica muscularis does not
appear as a definite layer or bundles of fibers, but appears as isolated
smooth muscle fibers which run within the vascular connective tissue. In
addition, the oviduct is surrounded with ill-defined serosa in most parts,
and adventitia in the most caudal part of the vagina. When the geese
reaches the age of sexual maturity and the egg laying period, the wall of
the oviduct appears to be formed of well-developed four layers: tunica
mucosa, submucosa, muscularis, and serosa. The tunica mucosa shows a
well developed longitudinal folds which appear in cross section as long
primary folds that may be divided to show secondary folds, and may have
tertiary folds, especially in the infundibulum and vagina. The lining
epithelium of the fold is ciliated pseudostratified columnar epithelium,
formed of ciliated columnar-shaped cells, secretory non-ciliated columnar
cells, and basal cells. The ciliated cells are more predominant in
infundibulum and vagina.
The lamina propria is fibrous connective tissue containing
fibroblasts, lymphocytes, blood vessels, collagen fibers and tubular
glands which deeply project from the epithelium into the lamina propria.
This is especially true in the glandular parts of the oviduct, which are the
neck part of the infundibulum, magnum, isthmus, and uterus. The
glandular parts are also found in vagina, not as secretory glands but rather
as a store house for spermatozoa. The tunica submucosa is made of
fibrous connective tissue, while the tunica musculosa is a well-developed
layer of smooth muscle fibers, which may be circular or longitudinal
according to the place where is the fibers are found. The smooth muscle,
layer is the thickest in the region of vagina, and the serosa, forms the
external sheath of the oviduct. The present study reveals that the neutral
and acidic mucopolysaccharides do not exist in the lining epithelium of
any part of the geese oviduct of immature birds. This could be explained
by the fact that the primitive epithelial cells are still did not differentiate
into ciliated and secretory cells, and there were no secretions produced.
However, once the geese reaches its age of sexual maturity, cell
differentiation occurs, and the secretory cells gain their secretory activity.
Expectedly, both the neutral and acidic mucopolysaccharides are present
in the lining epithelium of the oviduct of sexually mature birds.
The neutral mucopolysaccharides are also present in the glandular
cells of infundibulum neck, magnum, isthmus, uterus and the sperm
storage glands in the vagina. In contrast to that, the acidic
mucopolysaccharides do not exist in the glandular cells of infundibulum
neck, magnum, isthmus, and uterus but exist in the sperm storage glands
in the vagina. TEM study reveals that the ultrasructures of the surface
epithelium of the geese oviduct showed two types of cells, namely,
ciliated and non-ciliated granular or secretory cells. The secretory cells
possese,s high content of mitochondria, free ribosomes, RER profiles, and
lysosomes. The ciliated cells are narrow with an expanded apex carrying
the cilia and exhibit elongated or irregularly- shaped, euchromatic nuclei,
which were located in the wide luminal regions of the cells. Cilia are
cylindrical in shape and are identical in length.
The present study documented that the secretory granules are
present either in the secretory cells of the lining epithelium, or in the cells
lining the proprial glands. The secretory granules are electron- lucent, of
medium to large size, and are present either above the level of the nucleus
(supra-nuclear) or under the level of the nucleus (infra-nuclear.