LESSON 20 cortas

The lining epithelium of the small intestine mucosa is composed of absorptive enterocytes, goblet cells, and occluding junctions that prevent content from diffusing. Enterocytes have an ovoid nucleus, microvilli, and a well-developed smooth endoplasmic reticulum. Goblet cells synthesize mucinogen and produce mucus that forms a protective film on the intestinal surface.

The lamina propria is richly vascularized and innervated loose connective tissue containing immune cells, diffuse lymphoid tissue, and lymphatic vessels. It also contains intestinal glands (crypts of Lieberkühn) that produce absorbent columnar cells and goblet cells.

Paneth cells, also known as eosinophilic granular cells, produce antimicrobial components and are located at the base of the crypts in the small intestine mucosa.

<p>The muscularis mucosae consists of two layers of smooth muscle, internal circular and external longitudinal, and is responsible for the peristaltic movements of the intestine.</p> Signup and view all the answers

<p>Brünner's glands are glands that produce mucous secretions and are located in the duodenum and horse intestines.</p> Signup and view all the answers

<p>The Auerbach's myenteric plexus is responsible for innervating the muscularis in the submucosa of the small intestine.</p> Signup and view all the answers

<p>The large intestine is responsible for microbial action, absorption of water, electrolytes, and vitamins. In horses and pigs, it also absorbs fatty acids produced by microbial digestion of cellulose.</p> Signup and view all the answers

<p>The small intestine mucosal glands are responsible for the renewal of the intestinal epithelium by producing absorbent columnar cells and goblet cells. At the base of the crypts, undifferentiated cells multiply, differentiate, and migrate to the villi, where they give rise to new cells.</p> Signup and view all the answers

<p>Apoptosis is a physiological process through which cells at the apex of the villi die and shed into the lumen.</p> Signup and view all the answers

<p>The endocrine cells of the APUD system, also known as enteroendocrine cells, secrete hormones and regulate the peristaltic movements of the gastrointestinal tract and its secretions.</p> Signup and view all the answers

<p>Peyer's patches contain M cells, which capture antigens from the intestinal lumen and present them to lymphocytes.</p> Signup and view all the answers

<p>Enterocytes absorb amino acids, monosaccharides, and immunoglobulins.</p> Signup and view all the answers