Functional morphology of the esophagus of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae)

2015 ◽  
Vol 65 (2) ◽  
pp. 177-191
Author(s):  
Sirlene Souza Rodrigues-Sartori ◽  
Katiane de Oliveira Pinto Coelho Nogueira ◽  
Vinícius Albano Araújo ◽  
Clóvis Andrade Neves
Keyword(s):  
Functional Morphology ◽  
Food Habits ◽  
Endocrine Cells ◽  
Esophageal Mucosa ◽  
Anterior Portion ◽  
Argyrophil Cells ◽  
Morphological Studies ◽  
Ciliary Action ◽  
Acid Mucins ◽  
Hemidactylus Mabouia

In order to understand the biology of species that easily establish themselves in new environments, morphological studies are essential. This study aimed to describe the esophageal functional morphology ofHemidactylus mabouia, indicating adaptations to food habits. Seventeen adult specimens were used for anatomical, topological, histological, and histochemical analyses. Histological sections were stained with toluidine blue or submitted to techniques for identification of argyrophil and argentaffin endocrine cells, proteins, and glycoconjugates. The esophagus ofH. mabouiais a tubular straight-lined organ, and its anterior portion is dilated, facilitating the swallowing of whole prey. The esophageal epithelium is pseudostratified, containing cells secreting neutral and acid mucins. At the esophagogastric transition, we found a mixture of this epithelium with a simple prismatic epithelium secreting neutral mucins. The esophagus lamina propria is thin and non-glandular. At the esophagogastric transition it becomes thick and filled by branched simple acinous glands, with cells secreting neutral mucins, zymogenic cells, and argentaffin endocrine cells, with no argyrophil cells. The mucins protect the esophageal mucosa and lubricate the channel to facilitate the passage of food, while pepsinogen in the stomach increases the levels of pepsin for proteolytic digestion. The muscular tunica is made up of smooth muscle cells. Ciliary action, in addition to muscle contractions, facilitates the swallowing of small prey.

A study of the posterior esophagus in the winter flounder, Pleuronectes americanus, and the yellowtail flounder, Pleuronectes ferruginea: morphological evidence for pregastric digestion?

1994 ◽  
Vol 72 (7) ◽  
pp. 1191-1198 ◽  
Author(s):  
Harry M. Murray ◽  
Glenda M. Wright ◽  
Gregory P. Goff
Keyword(s):  
Light And Electron Microscopy ◽  
Circular Muscle ◽  
Goblet Cells ◽  
Winter Flounder ◽  
Morphological Evidence ◽  
Esophageal Mucosa ◽  
Pleuronectes Americanus ◽  
Yellowtail Flounder ◽  
Acid Mucin ◽  
Acid Mucins

The morphology and the histochemistry from the mucus of the posterior esophagus of the winter flounder and the yellowtail flounder were examined using light and electron microscopy. The esophageal mucosa of both species was organized into elaborate branching folds. The epithelium consisted of a stratified layer of cuboidal cells interspersed with mucus-producing goblet cells. The cuboidal cells in the surface layer also exhibited a secretory function and were characterized by Golgi-associated granules and apical micoridges. These cells were termed esophageal surface secreting cells (ESSCs). The granules of the winter flounder ESSCs were ultrastructurally similar to mucous granules, whereas those of the yellowtail flounder were reminiscent of serous granules. Both types were analogous to those associated with salivary glands in mammals. Both goblet cells and ESSCs from the winter flounder stained positive for sulphated acid mucins, whereas in the yellowtail flounder goblet cells stained positive for sulphated and nonsulphated acid mucin combinations and ESSCs stained only for nonsulphated acid mucins. A pregastric digestive function is proposed, based upon the thick muscularis externa composed of striated circular muscle, the increased surface area due to mucosal folding, the complex histochemistry of the mucus, and the secretory nature of the ESSCs.

Neuroendocrine structures of the small intestine of the capybara Hydrochoerus hydrochaeris (Mammalia, Rodentia)

2018 ◽  
Vol 68 (1) ◽  
pp. 89-104
Author(s):  
Sirlene Souza Rodrigues Sartori ◽  
Juliano Vogas Peixoto ◽  
Vanessa de Paula Guimarães Lopes ◽  
Alfredo José Afonso Barbosa ◽  
Clóvis Andrade Neves ◽  
...  
Keyword(s):  
Small Intestine ◽  
Endocrine Cells ◽  
Nerve Fibers ◽  
Specific Staining ◽  
Histological Techniques ◽  
Argyrophil Cells ◽  
Hydrochoerus Hydrochaeris ◽  
Staining Techniques ◽  
Hematoxylin And Eosin ◽  
Hematoxylin And Eosin Staining

AbstractA complex network of nerve fibers of the enteric nervous system and enteroendocrine cells is known to regulate the gastrointestinal tract. The distribution and frequency of the argyrophil, argentaffin and serotonin immunoreactive endocrine cells and of the submucosal and myenteric nervous ganglia were studied in the small intestine of the capybaraHydrochoerus hydrochaeris, aiming to verify the existence of possible numerical correlations between endocrine cells and nervous ganglia. Fragments of the duodenum, jejunum and ileum of adult animals were collected and processed according to routine histological techniques. To study the nervous ganglia, hematoxylin and eosin staining was used, while specific staining techniques were used to study the argyrophil, argentaffin and serotonin immunoreactive endocrine cells: Grimelius, modified Masson-Fontana and peroxidase anti-peroxidase, respectively. Endocrine cells were more abundant in the area of the crypts and, in relation to their morphology, ‘open type’ endocrine cells prevailed. The population of argyrophil cells was larger than that of argentaffin cells, and these cells were larger than serotonin immunoreactive cells. The frequency of endocrine cells was apparently greater in the duodenum, indicating the importance of this intestinal segment in digestive and absorptive functions. Prominent nervous ganglia were observed in the submucosal and myenteric plexi, and were larger and more frequent in the myenteric plexus. A numerical correlation was found among the endocrine cells (argentaffin and serotonin immunoreactive cells) and the myenteric nervous ganglia, suggesting the presence of physiological interactions among the endocrine and nervous systems for the control of intestinal activities. The findings in this study contribute to the understanding of the digestive processes of this species, which may also help in its conservation and future survival.

Functional morphology of the gut of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae)

2014 ◽  
Vol 64 (3) ◽  
pp. 217-237 ◽  
Author(s):  
Sirlene Souza Rodrigues-Sartori ◽  
Katiane de Oliveira Pinto Coelho Nogueira ◽  
Alípio dos Santos Rocha ◽  
Clóvis Andrade Neves
Keyword(s):  
Small Intestine ◽  
Large Intestine ◽  
Endocrine Cells ◽  
Distal Segment ◽  
Predator Species ◽  
Submucosal Glands ◽  
Hemidactylus Mabouia ◽  
Species Being ◽  
Tubule Diameter

The purpose of this study was to characterize morphophysiological aspects of the gut of the gecko Hemidactylus mabouia, a predator species of tiny arthropods. Fourteen adult specimen of the gecko H. mabouia were euthanized and fragments of their small and large intestines were collected and processed according to routine methods for anatomical, topological, histological and histochemical analyses. Histological sections were stained with toluidine blue or submitted to techniques for identification of argyrophil and argentaffin endocrine cells, glycoconjugates and alkaline phosphatase activity. The small intestine of H. mabouia is much more extensive and convolute than the large intestine. There are subtle regional differences along the small intestine, as the tubule diameter and height of the inner folds noticeably decrease from the proximal toward the distal segment. There is no caecum between the small and large intestines and the abrupt change in the caliber marks the transition of the small intestine into the large intestine. The large intestine consists of a very dilated proximal segment followed by a short distal segment. The villi are absent, but the tall folds in the internal covering of the small intestine constitute important amplifier structures of the digestive and absorptive area. No mucosal or submucosal glands were observed along the intestine. The epithelial lining of the entire intestine is simple columnar with enterocytes, mucus-secreting cells and endocrine cells. The enterocytes are abundant in the small intestine and the mucus-secreting cells are abundant in the large intestine, which reflects the functional role of these organs. In sum, H. mabouia has small intestine that is longer than the large intestine, which is consistent with the species being a carnivorous reptile.

Extrapancreatic islets of Langerhans: ontogenesis and alterations in diabetic condition

1997 ◽  
Vol 153 (1) ◽  
pp. 73-80 ◽  
Author(s):  
M Bendayan ◽  
I-S Park
Keyword(s):  
Pancreatic Islets ◽  
Endocrine Cells ◽  
Adult Life ◽  
Duodenal Mucosa ◽  
Diabetic Rats ◽  
Adult Rat ◽  
Morphological Studies ◽  
Insulin Cells ◽  
Early Embryonic Stage ◽  
Different Strains

Abstract The existence of extrapancreatic islets in the duodenal mucosa of the adult rat has been established by morphological studies and the development of these islets has been followed from the early embryonic stage to neonatal and adult life. Like the pancreatic islets, glucagon cells were the first to appear at day 12 of gestation. However, in contrast to the pancreatic islets, insulin was not detected in the extrapancreatic islets until birth. At this stage, the different endocrine cells assume their classical topography, insulin cells being surrounded by non-insulin endocrine cells. In addition, the behaviour of these extrapancreatic islets in diabetic conditions was evaluated on streptozotocin-induced diabetic rats as well as on spontaneous BB Wistar diabetic rats. In both conditions, the extrapancreatic islets were found in the duodenal mucosa but were mainly composed of glucagon cells, the insulin cells having disappeared. These results demonstrate that the extrapancreatic islets are a common normal feature of the rat duodenal mucosa. They appear during fetal development, are present in different strains of rats and behave similarly to the pancreatic islets under spontaneous or chemically induced diabetic conditions. Although their exact role remains to be established, they probably react to local hyperglycaemic environment due to intestinal absorption. Journal of Endocrinology (1997) 153, 73–80

Functional morphology of the temporal region in the Rhynchocephalia

2003 ◽  
Vol 40 (4) ◽  
pp. 589-607 ◽  
Author(s):  
Xiao-Chun Wu
Keyword(s):  
Functional Morphology ◽  
Common Ancestor ◽  
Lateral Side ◽  
Temporal Region ◽  
Anterior Portion ◽  
Primitive State ◽  
Bone Structures ◽  
Jaw Musculature

Study of the functional morphology of the temporal region of the Rhynchocephalia by means of the analysis of jaw musculature and bone structures in living lepidosaurians suggests that the streptostyly of the quadrate is a derived state in the Lepidosauria and that its origin may have been coupled with the loss of the M. pterygoideus atypicus. Further, this analysis supports the view that the retention of a fixed quadrate in early rhynchocephalians with an incomplete lower temporal bar may have been required for precise tooth occlusion and suggests that a solid lower temporal bar in later rhynchocephalians may have served as a brace to support the lateral side of the quadrate condyle and thus prevent it from twisting anteriorly rather than posteriorly during the jaw cycle. It is hypothesized that a common ancestor shared by the Rhynchocephalia and Squamata had a skull with an incomplete lower temporal bar but a rigid quadrate. It is also hypothesized that the presence of the anterior portion of the M. pterygoideus (MPT) is a primitive state, and that the size of the pterygoid flange may have been a good indicator of the presence of the anterior portion of the MPT in fossil reptiles. As in Sphenodon, if the mandible is able to move anteroposteriorly, it must retract first during the jaw cycle in those reptiles in which a pterygoid flange is retained.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

Ultrastructure of the Parotid Gland of the Nine-Banded Armadillo

1977 ◽  
Vol 35 ◽  
pp. 640-641
Author(s):  
J. R. Ruby
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Periodic Acid ◽  
Acinar Cells ◽  
Duct System ◽  
Parotid Glands ◽  
Dasypus Novemcinctus ◽  
Anterior Portion ◽  
Periodic Acid Schiff ◽  
Thin Sections

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Chromic Acid Etching of Polyethylene

1973 ◽  
Vol 31 ◽  
pp. 72-73
Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard
Keyword(s):  
Chromic Acid ◽  
Low Cost ◽  
Acid Etching ◽  
Crystalline Morphology ◽  
Bulk Specimen ◽  
Morphological Studies ◽  
Perfect Form ◽  
Molecular Length ◽  
Lamellar Texture ◽  
Cost Studies

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.

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