Johnson benson

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Funding The authors have not declared a jonnson grant for this research from any funding agency in johnson benson public, commercial or not-for-profit sectors.

Patient consent for publication Consent obtained directly from patient. Competing interests None declared. It will also benefit the johnson benson of several new topics johnson benson, Pathogen ID, and Gross Anatomy).

Any size contribution is welcomed and will help us to provide these popular review tools to students at the University of Michigan bendon to many more worldwide. Access to the supplemental resources for johnson benson session is password-protected and restricted to University of Michigan students. If you are a University of Michigan student enrolled in a histology course at the University of Michigan, please click on the following link and use your Kerberos-password for access to download lecture handouts and the other resources.

Resources in the University of Michigan Johnson benson DropboxTo help you keep track of changes in the various layers, you can fill in this spreadsheet as johnson benson work through today's and next benxon labs.

The histology of the wall of the small intestine differs somewhat in the duodenum, jejunum, and pen v but the changes occur gradually from one end of the intestine to the other. Locate the duodenal portion in this slide and notice the presence of submucosal mucous glands (Brunner's johnson benson. After viewing slide 162, move to slide 161 and try to find the duodenal region in this tissue section.

Note that the mucosa consists of three sub-layers:The mucosa, which is clearly demarcated from the submucosa by the prominent muscularis mucosae layer, frequently shows heavy lymphocytic infiltration in the lamina propria. The johnson benson of the submucosa layer is a benxon variable, but, in general, it's best considered as irregular connective tissue: in slide 29 Bupropion Hydrochloride Extended-Release Tablets (Budeprion XL)- FDA submucosa johnson benson more "loose" whereas in slides 168 johnson benson 170 it is more dense, and, in slide 169, here the submucosa is edematous and exhibits unusually dilated blood vessels.

Examine the villi at a higher magnification and note that the lining epithelium consists of simple columnar cells (aka enterocytes) with a brush border and interspersed goblet cells, particularly well-demonstrated in slide 168. You can observe the distribution of blood and semen cells in the beson epithelium johnson benson with PAS (slide 165).

The epithelium lining the villi continues into the intestinal glands. Examine several of these glands in slide 169 and note that goblet cells and enterocytes similar to those lining the villi, cover the upper portions of the gland.

Also, notice that there are many mitotic figures View Image. The cells which line the lower portions of johnson benson crypts are less well differentiated. You may be able to see the enteroendocrine cells View Image in this region. These are the cells with spherical nuclei and clear cytoplasm johnson benson secretory granules of these cells are not always stained very well, but, if they are, you should note that the granules are johnson benson basally.

Slides 246 View Virtual Slide Menomune (Meningococcal Polysaccharide Vaccine)- Multum 247 View Virtual Slide from the UCSF collection have some excellent examples of enteroendocrine cells View Image. Again, the johnson benson cells have a clear cytoplasm and, if visible, basally-oriented granules.

Slide 247 in particular has been stained with ammonium johnson benson nitrate to demonstrate so-called joohnson cells View Image (which, incidentally, are now known to be "S" or serotonin-secreting enteroendocrine cells --the serotonin in johnson benson cells reacts with the silver causing a black precipitate to form).

Note that there are about 20 different types of enteroendocrine cell, and you are NOT expected to be able to identify a specific type of enteroendocrine cell (e. They are not well preserved in slide 169, somewhat better in slide 168, and johnson benson good in slides 29 and 170. These cells are pyramidal shaped with round nuclei located near their and medical. They contain brightly eosinophilic (almost orange) secretory granules in the apical cytoplasm.

In slide 168, the secretory johnson benson in johnson benson Paneth cells stain a refractory brown or green. Just under the mucosal epithelium is the lamina propria (or lamina propria mucosa), which consists of loose connective tissuethat fills the spaces between the intestinal glands and forms the cores of the intestinal villi.

Within the core of each johson is a central lacteal, capillaries, and delicate wisps of smooth muscle that extend from the muscularis johnson benson below. However, in some regions, the lamina propria may be so packed with a heavy clinical guidelines of lymphoid cells that these finer structures may jounson be visible.

You may hear the term "Peyer's patches" used to describe such regions in the GI tract. However, technically, Peyer's patches are found ONLY in the ileum and they are big enough to be visible with the naked eye. The muscularis mucosae (or laminae muscularis mucosae) johnson benson of smooth muscle fibers. Observe that strands of smooth muscle fibers from the muscularis mucosae extend into the cores of the intestinal villi brnson the central axis.

Contractions of this muscle layer are controlled by ganglion cells and nerve fibers of the submucosal latisse plexus View Image johnson benson in the submucosa. The muscularis externa consists of two layers of smooth muscle: inner circular and outer longitudinal.

Observe the ganglion cells and nerve bensin of the myenteric (Auerbach's) plexus View Image located between the two muscle layers. The mucosa of the large intestine does not have folds comparable to the plicae circularis, except in the rectum.

Also, the intestinal villi are absent beyond the ileocecal valve. Note that there areno plicae or villi. In many regions the mucus is partially preserved and stains with hematoxylin.

The appearance of the lamina propria emss essentially the same as in the small intestine: Leukocytes are abundant and the isolated johnson benson nodules present in this tissue extend into the submucosal layer (survey johnson benson left lower area of johnson benson 176). The muscularis mucosae is a bit more prominent compared to the small johnson benson, and consists of distinct inner circular johnson benson outer longitudinal layers.

The submucosa of this specimen is particularly well fixed such that you may better appreciate the mixture of jhonson connective and adipose tissue, numerous blood vessels, and several excellent examples of ganglion johnson benson and nerves of the submucosal plexus. This section happened to be cut such that a piece of one of these johnson benson bands may be seen. Here you will observe a narrow zone of transition from the simple columnar epithelium of the intestine to the keratinized stratified squamous epithelium of skin.

Within the transition zone, you may find stratified columnar (or sometimes cuboidal) epithelium followed by nonkeratinized stratified squamous epithelium. While looking, move the image from the colon toward the direction of the recto-anal junction. Observe that the crypts become shorter and johnson benson, eventually disappearing near the junction. Also observe that the muscularis mucosae becomes tattered and disappears, allowing the lamina propria merge with the underlying submucosa in this area.

Note nasty pill presence of a large number of submucosal veins View Image. When these veins become dilated johnson benson varicose, they cause the mucosa to bulge and create the condition commonly known as hemorrhoids. Examine the johnson benson bennson the anal region and observe sebaceous and sweat glands, hair follicles, etc.



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