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Secretory Units (secretory + unit)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

Serous cutaneous glands in the South American horned frog Ceratophrys ornata (Leptodactylformes, Chthonobatrachia, Ceratophrydae): Ultrastructural expression of poison biosynthesis and maturation

JOURNAL OF MORPHOLOGY, Issue 8 2007
Irina Arifulova
Abstract Serous cutaneous glands are described in newly metamorphosed and juvenile specimens of the horned frog Ceratophrys ornata using light and transmission electron microscopy. We report patterns of biosynthesis and maturation of the specific product of the gland secretory unit. The syncytial, secretory compartment possesses a complex of endoplasmic reticulum (predominantly smooth endoplasmic reticulum after metamorphosis) and Golgi stacks. The serous product is weak in density and is contained in vesicles involved in repeating merging processes. During this maturation activity, secondary lysosomes are observed, which derive from autophagic processes (crinophagy) involving the secretory materials. Ceratophrys ornata, a species representative of the type genus of the family Ceratophrydae, belongs to the heterogeneous group of anurans that, possibly as the result of convergence, all produce cutaneous poisons consisting of vesicles or faint density granules. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source]

The subepithelial gland in ants: a novel exocrine gland closely associated with the cuticle surface

ACTA ZOOLOGICA, Issue 4 2003
Bruno Gobin
Abstract Two glandular systems were discovered that secrete their products onto the cuticular surface in ants. The first, the subepithelial gland, was previously undescribed in ants, and is found throughout the body just beneath the epithelium. This gland consists of independent secretory units, each made up of a single gland cell and an associated duct cell that penetrates the cuticle. Its ultrastructural appearance is consistent with possible hydrocarbon production. Examining 84 ant species, the subepithelial gland was found in eight subfamilies (out of 13), although not necessarily in all species. In a single ant species, Harpegnathos saltator, it was the epithelium itself that was enlarged and functioned as a gland. The enlarged epithelial cells secrete their products directly onto the cuticle through distinct cuticular crevasses. [source]

Structure of the Oesophagus and Morphometric, Histochemical,Immunohistochemical Profiles of the Oesophageal Gland During the Post-hatching Period of Japanese Quails (Coturnix coturnix japonica)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009
H. Sa
Summary In the oesophagus, mucins, which originate from oesophageal submucosal glands, play an important role in the mucosal protection as a pre-epithelial barrier. In this study, the structure of cervical and thoracic parts of oesophagus of Japanese quail during the post-hatching period was compared, and the contents of carbohydrate and gastric mucin MUC5AC of the oesophageal glands in these parts were analysed at the light microscope levels by applying conventional histochemical and immunohistochemical methods. The oesophageal glands were present at hatching, located in the laminae propria. The numbers of glands were different in the cervical and thoracic parts, but the differences were found to be insignificant. The thoracic part has the oesophageal tonsils which are associated with the glands. Oesophageal tonsil was formed from day 5 after hatching. In quail of all ages, the secretory epithelium of glands contained neutral sialomucins and weakly sulphomucins. The cells in the neck region of secretory units contained sialomucins, while the cells of excretory ducts had strongly sulphomucins. Sialomucin containing cells in the secretory units increased with the advance of age and glandular development. But, in the secretory units, the sulphomucin content of glands was more in the thoracic part. The secretory epithelium of tonsil-associated glands contained mostly sulphomucins and a little sialomucin. From the hatching, MUC5AC mucin was detected in the cells of excretory ducts. Although the lymphoepithelium of the tonsil units exhibited negative reactions to all histochemical methods, it showed positive reaction to MUC5AC mucin antibody. In conclusion, the cervical and thoracic parts may be functionally different and the thoracic part of oesophagus was transformed into an immunological organ following day 5 after hatching. [source]

The Gross and Micro Anatomy of the Accessory Sex Glands of the Male Agouti (Dasyprocta leporina)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009
W. M. Mollineau
Summary This study was a follow up to the study on the gross anatomy of the male agouti (Dasyprocta leporina) reproductive system. The seminal vesicles of the agouti are lobulated structures. The mean diameter of the large lumen is 883.6 ± 76.83 ,m. The mucosa (24.1 ± 0.92 ,m), which is lined by pseudo-stratified columnar epithelium is thrown into folds, which often branch. The lamina muscularis mucosa is thin and is made of loose connective tissue containing blood vessels. The mucosa of the leaf-like coagulating glands of the agouti is folded. The mean diameter of the lumen is 488.3 ± 41.96 ,m. The mucosa contains tubuloalveolar glands, which have a mean length of 199.5 ± 28.83 ,m. The thin epithelium, 15.0 ± 1.25-,m wide, consists mostly of pseudo-stratified columnar cells. The epithelium also has surface modifications in the form of apical blebs and cilia. The epithelium of the agouti's lobulated prostate gland is also folded creating a large lumen with a mean diameter of 995.5 ± 55.70 ,m. The mucosa contains tubular and tubuloalveolar glands, each having a mean length of 134.4 ± 13.59 ,m. The epithelium (13.9 ± 1.16 ,m) consists of pseudo-stratified columnar cells. The pea-shaped bulbourethral gland (BG) of the agouti consists of convoluted tubular, mucous secretory units, which are irregularly shaped each with a mean length of 177.9 ± 7.10 ,m and a mean width of 63.5 ± 3.97 ,m. The BG of the agouti are ventro-lateral to the rectum and dorsally positioned to the pubic symphysis, and connected to the urethra by short ducts. [source]