Latest revision as of 14:18, 21 February 2025

Duodenum[edit]

The duodenum is the first section of the small intestine in most higher vertebrates, including humans. It is a hollow jointed tube connecting the stomach to the jejunum.

Anatomy[edit]

The duodenum is approximately 25–30 cm (10–12 inches) long and is shaped like a "C". It is divided into four parts:

The superior part
The descending part
The horizontal part
The ascending part

The duodenum is located in the upper abdomen and is mostly retroperitoneal, meaning it is located behind the peritoneum.

Histology[edit]

Histological section of the duodenum showing the villi.

The duodenum has a unique histological structure that includes:

Villi: Finger-like projections that increase the surface area for absorption.
Microvilli: Microscopic projections on the surface of the villi.
Brunner's glands: Located in the submucosa, these glands secrete an alkaline mucus that helps neutralize gastric acid.

Microvilli of the duodenum under a microscope.

Function[edit]

The primary function of the duodenum is to receive the chyme from the stomach and continue the process of digestion. It also plays a crucial role in:

Neutralizing stomach acid
Mixing chyme with digestive juices from the pancreas and bile from the liver
Absorbing nutrients such as iron and calcium

Clinical Significance[edit]

The duodenum can be affected by various diseases and conditions, including:

Duodenal ulcer: A common form of peptic ulcer disease.
Celiac disease: An autoimmune disorder affecting the small intestine.
Giardiasis: An infection caused by the parasite Giardia lamblia.

Development[edit]

The duodenum develops from the foregut and midgut during embryogenesis. It is initially a solid cord of cells that later becomes a hollow tube.

Related Pages[edit]

Gallery[edit]

Diagram showing the position of the duodenum in the digestive system.
Anatomy of the small intestine, including the duodenum.
Illustration of the duodenum and its relation to surrounding organs.

@@ Line 1: / Line 1: @@
-{{Short description|The first section of the small intestine in most higher vertebrates, including humans}}
+= Duodenum =
-{{Anatomy}}
-The '''duodenum''' is the first section of the [[small intestine]] in most higher vertebrates, including humans. It plays a crucial role in the digestive process by receiving partially digested food from the [[stomach]] and beginning the absorption of nutrients.
+The '''duodenum''' is the first section of the [[small intestine]] in most higher vertebrates, including humans. It is a hollow jointed tube connecting the [[stomach]] to the [[jejunum]].
-==Anatomy==
+== Anatomy ==
-The duodenum is approximately 25 to 30 centimeters (10 to 12 inches) long and is shaped like a "C". It is located just below the [[stomach]] and is connected to the [[pylorus]], the opening from the stomach into the duodenum. The duodenum is divided into four parts:
-===First Part===
+[[File:Tractus_intestinalis_duodenum.svg|thumb|right|Diagram of the duodenum and surrounding structures.]]
-The first part, also known as the superior part, is about 5 centimeters long. It begins at the pylorus and extends to the neck of the [[gallbladder]]. This section is intraperitoneal and is the most mobile part of the duodenum.
-===Second Part===
+The duodenum is approximately 25–30 cm (10–12 inches) long and is shaped like a "C". It is divided into four parts:
-The second part, or descending part, is about 7 to 10 centimeters long. It runs vertically downward in front of the right kidney. This section receives the [[bile]] and [[pancreatic juice]] through the [[major duodenal papilla]].
-===Third Part===
+# The superior part
-The third part, or horizontal part, is about 10 centimeters long. It crosses horizontally from right to left, passing in front of the [[inferior vena cava]], the [[aorta]], and the [[vertebral column]].
+# The descending part
+# The horizontal part
+# The ascending part
-===Fourth Part===
+The duodenum is located in the upper abdomen and is mostly retroperitoneal, meaning it is located behind the [[peritoneum]].
-The fourth part, or ascending part, is about 2.5 centimeters long. It ascends on the left side of the aorta to the level of the second lumbar vertebra, where it turns abruptly forward to become the [[jejunum]].
-==Function==
+== Histology ==
-The duodenum plays a vital role in the digestive process. It is responsible for:
-* Receiving chyme from the stomach and neutralizing its acidity.
+[[File:Dogduodenum100x3.jpg|thumb|left|Histological section of the duodenum showing the villi.]]
-* Mixing chyme with bile and pancreatic juices to aid in digestion.
-* Beginning the absorption of nutrients such as iron and calcium.
-The duodenum's lining contains [[Brunner's glands]], which secrete an alkaline mucus that helps to neutralize gastric acid in the chyme.
+The duodenum has a unique histological structure that includes:
-==Clinical Significance==
+* [[Villi]]: Finger-like projections that increase the surface area for absorption.
-The duodenum can be affected by various medical conditions, including:
+* [[Microvilli]]: Microscopic projections on the surface of the villi.
+* [[Brunner's glands]]: Located in the submucosa, these glands secrete an alkaline mucus that helps neutralize gastric acid.
-* [[Duodenal ulcers]]: These are sores that develop on the lining of the duodenum due to excessive acid production or infection with [[Helicobacter pylori]].
+[[File:Microvilli-Duodenum.JPG|thumb|right|Microvilli of the duodenum under a microscope.]]
-* [[Celiac disease]]: An autoimmune disorder where ingestion of gluten leads to damage in the small intestine, including the duodenum.
-* [[Duodenitis]]: Inflammation of the duodenum, often caused by infection or irritation from stomach acid.
-==Images==
+== Function ==
-[[File:Duodenum anatomy.png|thumb|right|Diagram of the duodenum showing its four parts.]]
-[[File:Digestive system diagram.png|thumb|left|The duodenum is part of the digestive system, connecting the stomach to the jejunum.]]
+The primary function of the duodenum is to receive the chyme from the stomach and continue the process of digestion. It also plays a crucial role in:
+* Neutralizing stomach acid
+* Mixing chyme with digestive juices from the [[pancreas]] and [[bile]] from the [[liver]]
+* Absorbing nutrients such as iron and calcium
+== Clinical Significance ==
+[[File:Small_bowel_duodenum_with_amyloid_deposition_congo_red_10X.jpg|thumb|left|Duodenum with amyloid deposition.]]
+The duodenum can be affected by various diseases and conditions, including:
+* [[Duodenal ulcer]]: A common form of [[peptic ulcer disease]].
+* [[Celiac disease]]: An autoimmune disorder affecting the small intestine.
+* [[Giardiasis]]: An infection caused by the parasite ''Giardia lamblia''.
+[[File:Giardiasis_duodenum_low.jpg|thumb|right|Duodenum affected by giardiasis.]]
+== Development ==
+The duodenum develops from the foregut and midgut during embryogenesis. It is initially a solid cord of cells that later becomes a hollow tube.
+== Related Pages ==
-==Related Pages==
 * [[Small intestine]]
-* [[Digestive system]]
+* [[Jejunum]]
+* [[Ileum]]
+* [[Stomach]]
 * [[Pancreas]]
-* [[Bile duct]]
+== Gallery ==
+<gallery>
+File:Gray1058.png|Diagram showing the position of the duodenum in the digestive system.
+File:Blausen_0817_SmallIntestine_Anatomy.png|Anatomy of the small intestine, including the duodenum.
+File:Gray533.png|Illustration of the duodenum and its relation to surrounding organs.
+</gallery>
 [[Category:Digestive system]]
 [[Category:Gastroenterology]]

Duodenum: Difference between revisions