Title: Small Intestine - Parts, Function & Quiz | Biology Dictionary
Headings: Small Intestine
Small Intestine
Definition
Overview
Small Intestine Function
Digestion of Proteins
Digestion of Lipids
Digestion of Carbohydrates
Parts of the Small Intestine
Diseases of the Small Intestine
Inflammatory Bowel Disease
Small Intestine Cancer
Quiz
1. Which method of transport do amino acids follow?
Cite This Article
Subscribe to Our Newsletter

Content: While fructose can be structurally absorbed by cells via facilitated diffusion, glucose requires secondary active transport. Parts of the Small Intestine
The small intestine is further divided into three sections: the duodenum, the jejunum, and the ileum. The duodenum is the first and shortest section of the small intestine, which measures about fifteen inches long. It receives chyme (or, a mix of partially digested food particles that is mixed with bile) from our stomachs. The duodenum’s intestinal cells also secrete amylase, sucrase, and lipase enzymes that break down fats and sugars. The jejunum follows suit and is located near our belly buttons. The jejunum marks the end of our digestion of fats and carbohydrates. It is covered in villi and microvilli that make it the principal site of digestion. It is also a coiled structure that is thicker and has more blood vessels than the third and final section, the ileum.