Serosae

Four major tissue layers, from the lumen outward, form the large intestine the mucosa, submucosa, muscularis externa, and serosa (Fig. 88-2). Complete replacement of surface epithelial cells occurs approximately weekly, with the total number of epithelial cells remaining constant in normal colonic tissue. As patients age, abnormal cells accumulate on the surface epithelium and protrude into the stream of fecal matter their contact with fecal mutagens can lead to further cell mutations and eventual adenoma formation.4... 

Describe the anatomical and functional characteristics of each of the four layers of the digestive tract wall mucosa, submucosa, muscu-laris externa, and serosa... 

Postmortem findings include edema in the periorbital tissue, neck muscles, ligamentum nuchae, intermuscular and lungs hemorrhage of the tongue, intestinal serosa, kidneys, and pericardium and general subcutaneous edema and hemorrhage. 

Figure 8.1 (A) Cross-sectional view of the organization of the small intestine, illustrating the serosa, the longitudinal and circular muscle layers (=muscularis externa), the submucosa, and the intestinal mucosa. The intestinal mucosa consists of four layers, the inner surface cell monolayer of enterocytes, the basal membrane, the lamina propria (connective tissue, blood capillaries), and the muscularis mucosae, (B) Schematic representation of an enterocyte (small intestinal epithehal cell) (according to Tso and Crissinger [151], with permission).

Crohn s disease is granulomatous and in most cases it is a simultaneous disease of the ileum and colon. The primarily inflamed region is the distal ileum, and all intestinal layers are thickened. The mucosal surface is reddened, nodular, and cobblestone-Uke, with mnltiple linear ulcerations. The mucosal layer is thickened by inflammatory infiltrate, the submucosa and serosa by fibrosis, and the serosa by hypertrophy. Chronic nlcerative colitis is a systemic disease that starts at the rectum or the sigmoid colon and progresses proximally to involve the entire left side of the colon. The colonic crypts are the first sites of cell damage and death, and the disease primarily involves the mucosal layer of the intestine. 

In a chronic inhalation bioassay in rats exposed for 6 hours/day, 5 days/week for 2 years to 100, 33, or 10ppm ethylene oxide, there was a dose-related increased occurrence of mononuclear cell leukemia in both sexes at all concentrations. There was also an increased occurrence of primary brain tumors at 100 and 33 ppm in both sexes and peritoneal mesotheliomas arising from the testicular serosa at 100 and 33 ppm in male rats. ... 

Catgut sutures are seldom actually catgut. The name is derived from past practices. Today, so-called catgut is derived from the submucosa of sheep jejunum and the ileum or serosa of beef intestine that is cut into longitudinal ribbons. 

Tumor invades lamina propria or submucosa Tumor invades mucularis propria or subserosa Tumor penetrates the serosa (visceral involvement) without invasion of adjacent structures Tumor invades adjacent structures... 

T4 NO MO B3 Tumor invades through serosa (colon) or adjuvant organs... 

There is predisposition for the clinical involvement of skin, joints, muscles, peripheral and central nervous system, GI tract, kidneys, hearth, serosa and... 

Penicillin G (benzylpenicillin) is an acid-labile compound having variable bioavailability after oral administration. Consequently, penicillin G is most appropriate for intramuscular or intravenous therapy. The drug distributes to most tissues and serosa-lined cavities, although low concentrations appear in breast milk and... 

Bladder Mucosa, muscularis, serosa Holds urine... 

Rectum Mucosa, submucosa, muscularis externa, serosa Transports waste... 

Stomach Mucosa, submucosa, muscularis serosa Hydrolyzes food ... 

Serosa Fibroblasts Connective tissue Part of peritoneum... 

Food is propelled through the stomach by wall contraction in a similar manner to the way blood is pushed through blood vessels. The stomach and intestines contain several layers including the mucosa, submucosa, muscu-laris, and serosa. In the stomach the inner lining is made up of a mucous layer with columnar epithelium that extend into the gastric pits about 1/4 of the thickness of the wall (Figure 3.14). Below the epithelium is the lamina... 

Figure 3.14. Structure of the stomach. Stomach contains four layers, including the mucosa, submucosa, muscularis, and serosa. The inner infolded mucous layer is made up of columnar epithelium, and gastric pits are found within the infoldings. Submucosa contains connective tissue and vessels, and the muscularis contains muscle fibers. The serosa is on the outside of the stomach and is continuous with the peritoneum.

The next layer is the muscularis externa, which contains circular muscle fibers on the top layers and longitudinal muscle fibers on the outer layers. Finally, the serosa is found which is continuous with the peritoneum. Food movement through the stomach into the intestines occurs by contraction of the muscle fibers in the musclularis. 

The structure of the bladder, ureter, and urethra are similar in that they contain three layers, the mucosa, muscularis, and serosa. In the bladder (Figure 3.16) the inner layer (mucosa) when empty is infolded and it is made up of transitional epithelium. The lamina propria that is found below contains collagen and elastic fibers in the deeper layer. The muscularis is prominent and contains muscle fibers that are arranged in branching bundles separated by connective tissue. Muscular contraction causes expulsion of fluid from the bladder into the ureter. The connective tissue between the muscle fiber bundles merges with the connective tissue of the serosa. The serosa is continuous with the peritoneal lining. 

Figure 3.16. Structure of bladder. This structure is composed of mucosa, muscularis, and serosa. In the bladder, the mucosa is infolded when empty and is supported by connective tissue in the lamina propria. Muscularis contains smooth muscle bundles, and the serosa is continuous with the peritoneum.

Traditional endoscopic and surgical procedures provide whole tumor samples well suited for microscopic examination and analysis in the pathology laboratory. The use of whole tissue tumor biopsies for proteomic studies has, however, raised several important issues that have been well demonstrated in CRC [9]. These include cellular heterogeneity in the different bowel parietal layers (mucosa, submucosa, muscularis mucosa, serosa) that may or may not be infiltrated, epithelial cell diversity in the mucosa itself, tissue infiltration by inflammatory cells such as lymphocytes, contamination with other body fluids, and protein degradation following tumor necrosis. In fact, epithelial cell content was found to vary between 9 and 67% in whole biopsies of normal mucosa and between 7 and 95% in tumor biopsies [10]. This study clearly demonstrates the likelihood of large cellular variation between tissue samples. 

Interpretation of cryosections depends on tissue adequacy and staining adequacy. Tissue adequacy depends on the overall size and quality of each piece as well as whether the essential tissue components are adequately represented. For example, a piece of human uterus should have surface and glandular endometrium with endometrial stromal cells, muscular tunics, and, if possible, serosa (mesothelium). To ensure tissue adequacy, individual tissue cryosections should be used. Slides with multiple tissues (especially those with multiple small pieces—multitissue arrays) generally should not be used.2 These... 

---