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Major Digestive and Endocrine Glands
Published in George W. Casarett, Radiation Histopathology: Volume II, 2019
The exocrine glandular parenchyma is in the form of a compound tubuloalveolar gland containing purely serous alveoli. Each alveolus has a basement membrane of reticular fibers on which rests a single layer of pyramidal serous gland cells. In addition to these cells, central alveolar cells are present within alveoli. These central alveolar cells are duct cells, i.e., cells at the beginning of ducts surrounded by alveoli. The gland cells of a pancreatic alveolus usually do not become directly continuous with an intercalated duct in the way that more typical exocrine glands do. There are small secretory capillaries between the serous gland cells. Typical secretory ducts are lacking in the pancreas, but intercalated ducts are well developed and lined by a simple layer of flat or cuboidal epithelial cells. The excretory ducts are lined by a single layer of columnar epithelial cells.
Anatomy and Embryology of the Mouth and Dentition
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, Head & Neck Surgery Plastic Surgery, 2018
The parotid gland is the largest salivary gland. It is a serous gland. The parotid gland is situated in front of the external ear on the face and consequently will not be described further. The parotid duct runs through the cheek and drains into the mouth opposite the maxillary second permanent molar tooth. Its parasympathetic innervation is derived from the lesser petrosal branch of the glossopharyngeal nerve via the otic ganglion.
Gastrointestinal Tract
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
Judit E. Markovits, Graham R. Betton, Donald N. McMartin, Theresa Boulineau
Starting with the esophagus, the GI tract is mainly structured as a tube with some surface/structural modifications. The general architecture is similar in all regions and includes the mucosa surrounding the lumen, submucosa, and muscularis. The first segment of the tubular digestive tract is the esophagus, which is essentially a conduit between the oral cavity and the stomach. The esophageal mucosa is similar to that of the oral cavity and is composed of stratified squamous epithelium arranged in longitudinal folds. The esophagus has relatively poor vascularization resulting in delayed wound healing. In different regions of the submucosa, serous glands are present (especially in dogs). The muscular layer of the esophagus is noteworthy because its composition determines whether luminal contents can move only in one direction or both directions. Species with only smooth muscle in the muscularis, such as mice and rats, are not able to vomit. In contrast, dogs have only striated muscle, whereas primates and pigs have a mixture of smooth and striated muscle in the muscularis of the esophagus, and these species are able to vomit. Emesis is initiated either by mucosal information or by direct central nervous stimuli. In the context of toxicity testing in dogs, occasionally a change of large animal species from dogs to nonhuman primates (or pigs) is needed, because nonhuman primates (and pigs) are generally less sensitive to emetic stimuli than dogs who are prone to emesis due to mucosal stimuli that may cause limited bioavailability (van der Laan 2010).
Comparative studies on the tongue of the Egyptian fruit bat (Rousettus aegyptiacus) and the common quail (Coturnix coturnix)
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Amany Attaallah, Yousra Fouda, Abd El-Fattah B. M. El-Beltagy, Amira M. B. Saleh
The histological results of the present work revealed two types of lingual glands, serous glands on the lingual apex and body and mucus glands in the tongue of common quail; however, the tongue of R. aegyptiacus showed high density of serous glands. Additionally, the lingual intrinsic muscles appeared less developed in the tongue of common quail when compared to that of R. aegyptiacus tongue. Our findings match with the published reports on common quail [37,60] and R. aegyptiacus [57]. The watery and mucus secretions from the serous and mucus glands in the tongue of C. coturnix are necessary for mixing dry grains with water and mucus to facilitate swallowing by filiform papillae without injury. However, in R. aegyptiacus, the nature of feeding depends on soft fruits, so the watery secretions are more needed and this requires high density from lingual serous glands rather than the mucus glands. Similar declarations were recorded on the tongue of grainivorous birds like in white-headed duck [46], in domestic duck [45], in domestic goose [43] and in Anas crecca [44] as well as in fruit-eating bats [47,61,62]. The presence of well-developed lingual intrinsic muscles in the tongue of R. aegyptiacus comparatively with the tongue of common quail explains the lingual protrusible power of bat tongue to pick up the whole fruit.
Clinical profile and management outcomes of lacrimal drainage system malignancies
Published in Orbit, 2022
Md. Shahid Alam, Bipasha Mukherjee, Subramanian Krishnakumar
A review article published by Singh et al. and many of the published studies mention SCC as the most common lacrimal sac malignancy followed by TCC.2–4,15 The most common malignancy noted in our series was TCC (28.5%) followed by MEC (21.4%). SCC was seen in two of our cases (14.28%). Other tumors mentioned in literature are adenocarcinoma (ADC), adenoid cystic carcinoma (ADCC), and melanoma.2–4 The origin of glandular tumors like ADC and ADCC in the lacrimal sac has been questioned. It has been postulated that these glandular tumors could originate either from the mixed serous glands present in the wall of the LDS, or accessory/ectopic lacrimal glands present in the lacrimal sac tissue.18,19 The onset of melanoma in the lacrimal sac is difficult to explain since there are no melanocytes in the LDS. These melanocytes could be of ectopic origin and could have been arrested in the LDS during the migration of neural crest cells.20
Intranasal drug delivery devices and interventions associated with post-operative endoscopic sinus surgery
Published in Pharmaceutical Development and Technology, 2018
Lari K. Dkhar, Jim Bartley, David White, Ali Seyfoddin
The olfactory area is approximately 15 cm2 and is found in the roof of the nasal cavity which lies in-between the nasal septum and the lateral nasal wall. This area is mainly responsible for olfactory sensitivity. The neuroepithelium in the olfactory region is the only part of central nervous system (CNS) that is exposed to the external environment (Charlton et al. 2007; Trimmer and Mainland 2016). The nasal mucous area can be divided into two types: olfactory and non-olfaction epithelia region. The non-olfactory epithelium region is highly vascularized and is covered by pseudostratified columnar and ciliated epithelium. The olfactory epithelium comprises of specialized ciliated olfactory nerves projected into the nasal cavity essential for awareness of smell (Ugwoke et al. 2005; Trimmer and Mainland 2016). This olfactory area also comprises of supporting cells, mucous glands, and small serous glands (glands of Bowman). These small serous glands are producers of secretions acting as a solvent for odorous substances (Pires et al. 2009; Ghori et al. 2015; Trimmer and Mainland 2016).