Title: The Small Intestine | Boundless Anatomy and Physiology
Headings: The Small Intestine
The Small Intestine
Anatomy of the Small Intestine
Learning Objectives
Key Takeaways
Key Points
Key Terms
The Small Intestine
The Villi
Histology of the Small Intestine
Learning Objectives
Key Takeaways
Key Points
Key Terms
The Small Intestine’s Layers
Brunner’s Glands
Peyer’s Patches
Intestinal Villi
Digestive Processes of the Small Intestine
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Key Takeaways
Key Points
Key Terms
Chemical Digestion in the Small Intestine
Proteins
Lipids
Carbohydrates

Content: The muscularis is a region of muscle adjacent to the submucosa membrane. It is responsible for gut movement, or peristalsis. It usually has two distinct layers of smooth muscle: circular and longitudinal. The submucosa is the layer of dense, irregular connective tissue or loose connective tissue that supports the mucosa, as well as joins the mucosa to the bulk of underlying smooth muscle. The mucosa is the innermost tissue layer of the small intestines, and is a mucous membrane that secretes digestive enzymes and hormones. The intestinal villi are part of the mucosa. The three sections of the small intestine look similar to each other at a microscopic level, but there are some important differences. The jejunum and ileum do not have Brunner’s glands in the submucosa, while the ileum has Peyer’s patches in the mucosa, but the duodenum and jejunum do not. Brunner’s Glands
Brunner’s glands (or duodenal glands) are compound tubular submucosal glands found in the duodenum.