Changes

==Structure==

==Structure==

*The duodenum is the proximal part of the small intestine and extends from the pylorus of the stomach to the jejunum.

*The duodenum is the proximal part of the small intestine and extends from the pylorus of the [[Forestomach - Anatomy & Physiology|stomach]] to the [[Jejunum - Anatomy & Physiology|jejunum]].

*It has a sigmoid flexure upon leaving the stomach.

*It has a sigmoid flexure upon leaving the [[Forestomach - Anatomy & Physiology|stomach]].

*It has descending and ascending portions.

*It has descending and ascending portions.

**The descending duodenum passes out of the pylorus of the stomach (on the right side of the abdomen) and has a sigmoid flexure. It passes towards the right abdominal wall and rises  dorsally. In its passage it is related dorsally to the right lobe of the pancreas, ventrally to the jejunum and medially to the ascending colon and caecum.  

**The descending duodenum passes out of the pylorus of the [[Forestomach - Anatomy & Physiology|stomach]] (on the right side of the abdomen) and has a sigmoid flexure. It passes towards the right abdominal wall and rises  dorsally. In its passage it is related dorsally to the right lobe of the [[Pancreas - Anatomy & Physiology|pancreas]], ventrally to the [[Jejunum - Anatomy & Physiology|jejunum]] and medially to the ascending colon and caecum.  

**At a point between the right kidney and pelvic inlet it turns medially and cranially around the root of the mesentry to become the ascending duodenum. The point of turn is called the ''caudal flexure'' of the duodenum.

**At a point between the right [[Kidney - Comparative Anatomy & Physiology|kidney]] and pelvic inlet it turns medially and cranially around the root of the mesentry to become the ascending duodenum. The point of turn is called the ''caudal flexure'' of the duodenum.

**The ascending duodenum is shorter and bends ventrally to enter the mesentery and becomes the jejunum.

**The ascending duodenum is shorter and bends ventrally to enter the mesentery and becomes the [[Jejunum - Anatomy & Physiology|jejunum]].

*Mesoduodenum attaches the duodenum to the dorsal abdominal wall.  

*Mesoduodenum attaches the duodenum to the dorsal abdominal wall.  

**Within the mesoduodenum is the right lobe of the [[Pancreas - Anatomy & Physiology|pancreas]].

**Within the mesoduodenum is the right lobe of the [[Pancreas - Anatomy & Physiology|pancreas]].