Aedes Mosquitoes: The Universal Vector
Jagriti Narang, Manika Khanuja in Small Bite, Big Threat, 2020
Inside the hypopharynx, there is a salivary canal through which saliva flows. The saliva consists of many important proteins that include anticoagulant, vasodilating properties (Snodgrass, 1959). The digestive or alimentary canal consists of pharynx, esophagus, stomach divided into foregut, midgut, and hindgut, followed by intestine, rectum, and anus (Fig. 1.15). The nervous system consists of central, peripheral, and sympathetic systems with brain and ganglions connecting to all parts of the body (Fig. 1.16). On each side of the head is a compound eye consisting of hundreds of small units called ommatidia (Jirakanjanakit et al., 2008). The respiratory system includes spiracles on either side of the body, which open into tracheal trunks toward the inside of the body cavity (Mill, 1985, 1998; Sláma, 1999).
Normal fetal development and growth
Louise C Kenny, Jenny E Myers in Obstetrics, 2017
The primitive gut is present by the end of the fourth week, having been formed by folding of the embryo in both craniocaudal and lateral directions, with the resulting inclusion of the dorsal aspect of the yolk sac into the intraembryonic coelom. The primitive gut consists of three parts, the foregut, midgut and hindgut, and is suspended by a mesentery through which the blood supply, lymphatics and nerves reach the gut parenchyma. The foregut endoderm gives rise to the oesophagus, stomach, proximal half of the duodenum, liver and pancreas. The midgut endoderm gives rise to the distal half of the duodenum, jejunum, ileum, caecum, appendix, ascending colon and the transverse colon. The hindgut endoderm develops into the descending colon, sigmoid colon and the rectum.
Management of Acute Intestinal Ischaemia
Peter Sagar, Andrew G. Hill, Charles H. Knowles, Stefan Post, Willem A. Bemelman, Patricia L. Roberts, Susan Galandiuk, John R.T. Monson, Michael R.B. Keighley, Norman S. Williams in Keighley & Williams’ Surgery of the Anus, Rectum and Colon, 2019
The blood supply to the gastrointestinal tract arises primarily from three main branches of the abdominal aorta: the coeliac artery, the superior mesenteric artery (SMA) and the inferior mesenteric artery (IMA). The mesenteric vasculature can be highly variable, although there are certain constants that allow practitioners to formulate a diagnosis and management strategies. The coeliac artery primarily supplies the foregut from the distal oesophagus to the duodenum. The SMA primarily supplies the midgut, from the duodenum to the splenic flexure of the colon. The IMA primarily supplies the hindgut, from the splenic flexure of the colon to the upper rectum. The distal rectum is supplied by branches of the internal iliac (hypogastric) arteries via the middle and inferior rectal (haemorrhoidal) arteries.1 Blood flow to the gastrointestinal tract is approximately 1.5 to 1.8 L/min. The one constant throughout the gastrointestinal tract is that the blood supply comes from outside the gut via a variable mesentery, and the mucosa is the true ‘end organ’ and is therefore the most vulnerable to decrease in blood supply.
Gut non-bacterial microbiota contributing to alcohol-associated liver disease
Published in Gut Microbes, 2021
Wenkang Gao, Yixin Zhu, Jin Ye, Huikuan Chu
The term gut-liver axis was first described by Volta et al in 1987, which pointed out the interaction between intestine and liver.15 During the embryonic stage, both the liver and intestine originate from the same foregut, and the two organs are anatomically connected by the portal vein system after reaching their maturity.16 About 70 ~ 80% of the blood from the portal vein flows to the liver,17 transmitting a variety of signals generated by dietary, genetic, and environmental factors.(Figure 1)18 As a virtual metabolic organ, the gut-liver axis achieves close-knit functional collaboration and forms a sophisticated network structure through substance metabolism, immune regulation, and interaction with the neuroendocrine system.
Titanium dioxide nanoparticle exposure alters metabolic homeostasis in a cell culture model of the intestinal epithelium and Drosophila melanogaster
Published in Nanotoxicology, 2018
Jonathan W. Richter, Gabriella M. Shull, John H. Fountain, Zhongyuan Guo, Laura P. Musselman, Anthony C. Fiumera, Gretchen J. Mahler
The fruit fly D. melanogaster was used to extend these in vitro findings into an in vivo system. The fly gut is composed of foregut, midgut, and hindgut; paralleling the esophagus, small intestine, and large intestine of humans (Apidianakis and Rahme 2011). Like the human enterocytes, fly enterocytes contain apical-facing microvilli (Apidianakis and Rahme 2011). Drosophila melanogaster can tolerate TiO2 nanoparticles with low toxicity when fed concentrations typically found in the human diet (Jovanović et al. 2016). Previous work with D. melanogaster has shown some effects of TiO2 ingestion. For example, TiO2 exposure resulted in fewer eggs being laid (Philbrook et al. 2011). The effects on development appear variable, however, as different studies have observed either no effect (Philbrook et al. 2011; Posgai et al. 2011) an acceleration of development (this study) or a slowing of development (Lewandowski et al. 2008). The variable effects are likely due to myriad of differences between the studies, including the genetic backgrounds of the flies, the different types of TiO2 or sugar sources in the foods. Together these results suggest that the effects of TiO2 exposure will likely be influenced by the genotype of individuals and other components of their diet. Taken together, these data suggest that TiO2 has similar effects in in vitro gut cell co-cultures and the D. melanogaster gut.
Does transverse colon cancer spread to the extramesocolic lymph node stations?
Published in Acta Chirurgica Belgica, 2021
Bulent C. Yuksel, Sadettin ER, Erdinç Çetinkaya, Ahmet Keşşaf Aşlar
Although CME and CVL can be applied to all colon cancers, these procedures are slightly different in transverse colon cancers. The transverse colon shows embryological and anatomical oddities due to its midgut and hindgut origin and the location between the foregut and midgut-hindgut. The proximal 2/3 part is the end of the midgut while the distal part is the beginning of the hindgut. The proximal portion of the superior mesenteric artery and the foregut components, such as the great omentum, pancreas and lesser sac, are intertwined. This convoluted relationship suggests the possibility of an interaction between embryological areas. This relationship is even more evident in the venous drainage of the omentum and pancreas. These connections between embryological planes were described by Stelzner et al. in cadaveric studies [12]. In their prospective analysis, Perrakis et al. demonstrated tumor manifestation extending beyond this embryological area [13].