الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 160 |  |  |
| | | from | 160 | | |
Abstract
The materials used in the present study were colle
cted from Cairo slaughter house. They include 47 embryos
and fetuses of different CVR lengths (3.2—120 cm) beside
the salivary glands of 24 camels (1—20 years old).
The results presented in this investigation elucidate
the histological structure and its functional significance
of the dromedary camel during ontogenetic stages.
The primordium of the parotid salivary gland
originated from the bucczal ectodermal epithelium at the
mouth fissure at 3.2 Cm CVR length. The mandibular anlage
was developed from the epithelium of the oral cavity at
the linguogingival groove. The bud of the gland protruded
ventrocaudally leaving a fovea at its seat of origin. The
bud consisted of elongated mass of irregular shaped cells
with spherical centrally located nuclei and light
cytoplasm and could be observed in camel fetuses of 3~2 Cm
CVR length.
The sublingual gland anlage was formed from the
linguogingival groove at the root of the tongue as a
number of solid ducts. The sublingual primordium was
observed at 5.1 Cm CVR -length.
—64—
By the progressive division of the bud cells of the
parotid and the mandibular glands the bud grew and
extended as a main solid duct.
The cavitation was first started in the old parts of
the primordia. The onset of luminization was at the CVR
length 6.2 cm in the parotid and 5.1 Cm CVR length in the
mandibular gland.
The ramification of the primordia started at the CVR
length 5.1 Cm in the parotid, ventral buccal and
mandibular glands and at 6.2 Cm CVR length in other
glands.
The solid acini were first observed at the CVR length
13.6 Cm in the parotid, sublingual and buccal glands and
at 9.7 Cm in the mandibular. Each acinus consisted of a
mass of polygonal or irregul~tr cells with spherical
nuclei.
The lumZnization of the ramifonn primordia extended
into new branches. The walls of the luminized branches
were consisted of stratified columnar epithelium of two
cell layers. Scattered mucous cells were interposed
between the cells of the primordial branches. These cells
showed a high reactivity with alcian blue and PAS stains.
They were recorded at 23 Cm CVR length in the sublingual
-65—
and buccal glands while at 21 Cm and 17.5 Cm CVR length
among the parotid and the mandibular glands respectively.
With the advancement of age, the acini and the prim
ordial ducts proliferated. The mucous cells increased and
appeared in the cavitated acini at the CVR length 40 Cm
however in the mandibular at 21 Cm CVR length. The mucous
cells were very few in the paroti& acini. In the mandi
bular and sublingual glands the acinus consisted of
stratified columnar epithelium of two cell layers with the
mucous cells were restricted in the inner one. The cells
of the acini of the parotid and ventral buccal glands were
well organized in one layer without mucous cells. At late
pregnancy most of the acini were well developed. Each
acinus consisted of one layer of truncated pyramidal cells
with spherical nuclei and a narrow lumen. The parotid and
ventital buccal glands were well developed before birth.
The development of the end piece of the mandibular and the
sublingual glands were similar. The outer layer of the
acini gave the demilune while the inner layer gave the
mucous acinus. Well developed acini were seen at the CVR
length 65.6 Cm and most of then were well developed in the
prenatal life of all salivary glands.
Small clusters of serous acini were observed inter
posed between the lobules of mixed one in the sublingual
gland. These acini were detected by the absence of mucous
cells.
—66—
The main ducts of the talivary glands of the camel
were represented by the solid ducts produced by the
proliferation of the bud cells of each gland at 5.1 Cm Cfl
length. After luminization the duct cells arranged as
stratified columnar epithelium.
By the advancement of age, the epithelium of the main
duct of the parotid and the mandibular gland supported by
connective tissue propria carrying a number of blood
vessels and nerves. Gradually the lumen of the main duct
was folded and the goblet cells appeared among its
epithel ium.
The interlobular ducts were recognizable at the CVR
length 21 cm in case of the parotid and the mandibular
glands however at 27 cm CVR length in case of the
sublingual and buccal glands. They were composed of 2
layers of stratified columnar epithelium with goblet
cells.
The interlobular ducts of the dorsal and middle
buccal glands and sublingual gland were differentiated
into small one lined by simple columnar or even cuboidal
epithelium and larger one by 2 cell layers of stratified
columnar epithelium. The goblet cells were present in the
interlobular ducts in the prenatal life. They were few in
the sublingual and mandbular glands. However in the
67—
postnatal life the goblet cells were observed in the
interlobular ducts of the parotid, and ventral buccal,
very few in the mandibular and absent in the sublingual,
dorsal and middle buccal glands.
The striated ducts had never been recognized in the
prenatal life of all described salivary glands. The ducts
were observed in the prepubertal period and composed of
columnar cells with basal striation and surrounded by
myoepithelial cells. The striation diminished in senility
in the parotid and ventral buccal glands.
The camel salivary glands were compound branched
tubuloalveolar; they were seromucous.
The mesenchy~e (future stroma) of the aforementioned
salivary glands showed positive reaction by alcian blue
stain particularly at the early stages of pregnancy. The
stromal elements, the basement membranes and the free
borders of the ducts stained strongly by PAS stain. The
goblet cells as Well as the acini were showed PAS—positive
reaction in different stages of the prenatal life. So
secretory activity started during the period of mid
pregnancy. The reaction in the acini and the demilunes was
variable in the potnatal life. The acini of the parotid
and ventral buccal glands were alcian blue negative. The
variation in the alcian blue and PAS staining was due to
the different phases of secretion as storage, secretory
and exhaustion phases.