Duodenum vs. Jejunum — What's the Difference?
By Tayyaba Rehman — Published on December 27, 2023
The duodenum is the first part of the small intestine directly after the stomach, while the jejunum is the second part. Both play crucial roles in digestion.
Difference Between Duodenum and Jejunum
Table of Contents
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Key Differences
The duodenum and jejunum are two distinct parts of the small intestine. The duodenum is the first segment that directly follows the stomach. It's where a significant part of the digestion process begins, as it receives bile and pancreatic enzymes. On the other hand, the jejunum is the next segment of the small intestine that follows the duodenum.
The duodenum is relatively shorter than the jejunum. The former is a C-shaped structure that encircles the head of the pancreas. Within the duodenum, digestive juices mix with food, starting the process of nutrient breakdown. The jejunum, however, is where the majority of nutrient absorption takes place, including carbohydrates and proteins.
Both the duodenum and jejunum are vital in ensuring that our body gets the nutrients it requires. While the duodenum processes food with the help of bile and pancreatic enzymes, the jejunum is lined with villi, tiny hair-like structures that increase the surface area for absorption.
In summary, while both the duodenum and jejunum belong to the small intestine and are instrumental in digestion, they have unique roles. The duodenum begins the digestion, while the jejunum takes over the absorption.
Comparison Chart
Position in the intestine
First part of the small intestine
Second part of the small intestine
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Primary function
Digestion with bile and pancreatic enzymes
Absorption of nutrients
Structure
C-shaped structure around the head of the pancreas
Longer with villi for increased absorption
Length
Shorter
Longer
Relation to pancreas
Encircles the head of the pancreas
Located after the duodenum
Compare with Definitions
Duodenum
The initial section of the small intestine.
Food enters the duodenum right after leaving the stomach.
Jejunum
The mid-section of the small intestine.
Nutrients are absorbed in the jejunum after digestion.
Duodenum
Where bile and pancreatic juices mix with food.
Enzymes in the duodenum help break down nutrients.
Jejunum
The second part of the three segments of the small intestine.
The food moves from the jejunum to the ileum.
Duodenum
Directly follows the stomach in the digestive pathway.
Ulcers can sometimes form in the duodenum.
Jejunum
Lined with villi for enhanced absorption.
The villi in the jejunum increase the surface area for nutrient uptake.
Duodenum
Responsible for initiating digestion of food.
The duodenum processes the acidic chyme from the stomach.
Jejunum
Comes after the duodenum in the digestive sequence.
The chyme moves from the duodenum to the jejunum.
Duodenum
A C-shaped segment of the digestive tract.
The pancreas is enveloped by the duodenum.
Jejunum
Plays a key role in absorbing carbohydrates and proteins.
After being processed in the duodenum, nutrients are taken up by the jejunum.
Duodenum
The beginning portion of the small intestine, starting at the lower end of the stomach and extending to the jejunum.
Jejunum
The section of the small intestine between the duodenum and the ileum.
Duodenum
(anatomy) The first part of the small intestine, starting at the lower end of the stomach and extending to the jejunum.
Jejunum
(anatomy) The central of the three divisions of the small intestine which lies between the duodenum and the ileum
Duodenum
The part of the small intestines between the stomach and the jejunum. See Illust. of Digestive apparatus, under Digestive.
Jejunum
The middle division of the small intestine, between the duodenum and ileum; - so called because usually found empty after death.
Duodenum
The part of the small intestine between the stomach and the jejunum
Jejunum
The part of the small intestine between the duodenum and the ileum
Common Curiosities
What role does the duodenum play in digestion?
The duodenum starts the digestion process by mixing food with bile and pancreatic enzymes.
How does the jejunum assist in the digestive system?
The jejunum is vital for absorbing nutrients like carbohydrates and proteins.
Where is the jejunum located?
The jejunum is the second part of the small intestine, located after the duodenum.
What differentiates the jejunum from the ileum?
The jejunum is the second part of the small intestine, while the ileum is the third and last part.
Do both the duodenum and jejunum secrete digestive enzymes?
The duodenum receives digestive enzymes from the pancreas, while the jejunum primarily absorbs nutrients.
Is the duodenum longer than the jejunum?
No, the duodenum is shorter, while the jejunum is longer.
Can ulcers develop in the duodenum?
Yes, duodenal ulcers can form in the duodenum.
Which part of the small intestine receives bile?
The duodenum receives bile to help digest fats.
Do the duodenum and jejunum have similar structures?
While both are parts of the small intestine, the duodenum is C-shaped, and the jejunum is longer with villi.
Why is the jejunum lined with villi?
The villi in the jejunum increase the surface area for better nutrient absorption.
Is the jejunum crucial for nutrient absorption?
Yes, the jejunum plays a key role in the absorption of many nutrients.
Which part encircles the head of the pancreas?
The duodenum encircles the head of the pancreas.
What is the duodenum?
The duodenum is the first part of the small intestine that directly follows the stomach.
What comes after the jejunum in the digestive tract?
The ileum follows the jejunum in the digestive sequence.
Are the duodenum and jejunum both essential for digestion and absorption?
Yes, the duodenum initiates digestion, and the jejunum takes over absorption.
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Written by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.
