Samples from medial retropharyngeal, superficial cervical and deep femoral lymph nodes of four camels were fixed in neutral buffered formalin and prepared for light and electron microscopic examination. The camel lymph nodes were formed of stroma and parenchyma. A dense collagenous capsule and trabeculae beside fine reticular framework represented the stroma. The parenchyma was formed of follicular and non-follicular forms of lymphoreticular tissue. The lymphoid follicles were mainly secondary in nature formed of germinal center and outer corona. Afferent and efferent lymph vessels were noticed at the same area of the capsule. Capsular, subcapsular, trabecular, peritrabecular and parenchymal lymph sinuses were noticed in camel lymph nodes.

The present study aims to give detailed histomorphological features of the hippocampus of adult male New Zealand rabbits. Both histological and histochemical specimens were prepared to be examined microscopically by using a light microscope. The hippocampus appeared as C‐shaped hippocampal proper, dentate gyrus, and subiculum. The hippocampal proper subdivided along its length according to the density and size of its major constituent pyramidal cells into four distinct regions named Cornu Ammonis (CA1, CA2, CA3, and CA4). With the histochemical preparations, each of these regions consisted of five layers, stratum alveolus, stratum oriens, stratum pyramidale, stratum radiatum, and stratum lacunosum‐moleculare. The stratum pyramidale constituted the middle dark zone and contained the principal excitatory neurons and a few interneurons. Histochemically, the pyramidal neurons along all regions of the CA reacted positively to Grimelius silver impregnation, lead hematoxylin, Gomori's aldehyde fuchsin, aldehyde thionine, Gomori's chrome alum hematoxylin, and performic acid alcian blue stains. Immunohistochemically, the pyramidal neurons reacted positively to anti‐NSE antibodies. The dentate gyrus was formed of three distinct layers. The subiculum was formed of proper subiculum, presubiculum, and parasubiculum.

The present study aimed to clarify the light and electron microscopic structure of the prostate gland of mature (one-humped camels) during different seasons of the year. Glands of seventy-two mature healthy animals (5-7 years old) were collected from the Cairo slaughter house during one year, (6 samples each month) and prepared to be studied microscopically by the light and electron microscope. The prostate gland was found to be consisted of an external dorsal part dorsal to the neck of the bladder and an internal part situated in the submucosa of the prostatic urethra. During active season (winter and spring), the corpus prostate was enveloped by a thick fibromuscular capsule which sent septa, to divide the gland into lobules. The parenchyma formed of compound tubuloalveolar adenomeres. The alveoli and tubules were lined by high columnar cells and few basal ones. The acini appeared at different stages of secretory activity (synthesis, storage, secretion and exhaustion). Ultrastructurally, the acinar cells contained well developed rough endoplasmic reticulum (rER), numerous mitochondria and a variable number of secretory granules. The duct system began as central collecting sinuses lined by simple columnar secretory epithelium. The pars interna occurred in the submucosa of the prostatic urethra enveloped by a thick fibro-muscular band. The branched tubuloalveolar parenchyma contained adenomeres lined with simple cuboidal epithelium. During the inactive season (summer and autumn), the stroma showed a marked proliferation of the fibromuscular tissue on the expense of the parenchymatous tissue. The adenomeres became very small or even rudimentary with narrow lumina devoid of secretory materials. Marked reduction in the cytoplasmic organelles with a total absence of the secretory granules was also pronounced.

No abstract

The present investigation was conducted on the adrenal glands of 40 adult New Zealand rabbits of both sexes to characterize and identify the histological, histochemical, ultrastructural, and immunohistochemical features of the neurosecretory cells of the adrenal medulla. The obtained specimens of adrenal medulla were subjected to routine histological techniques and then stained with different histological stains, including general, non‐specific, specific, and highly specific stains for neurosecretory cells, in addition to immunohistochemical reactions. The obtained results showed two types of adrenal medullary neurosecretory cells containing secretory granules (SGs) of different electron densities: adrenaline and noradrenaline (NA) secreting cells. These secretory granules showed a strong positive reaction to the Grimelius silver impregnation technique. Sections stained with Gomori's chrome alum haematoxylin stain, and the secretory granules showed a strong dark blackish‐blue positive colour. The medullary cells showed typical chromaffin reactions when stained by H&E and Giemsa stains after formol dichromate ‘Ortha's fluid’ fixation. The noradrenaline secretory granules gave a strong positive Schmorl's test, while the adrenaline ones showed a moderate reaction. Immunohistochemically, the adrenal medullary cells were subjected to anti‐chromogranin A (CHGA) antibody using the PAP technique, which gave positive reactions.