Changes

==Structure==

==Structure==

*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.  

*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 - 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.

**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 - Anatomy & Physiology|jejunum]].

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

===Canine===

===Canine===

*The duodenum is about 25cm long.

*Duodenum is about 25cm long.

*The mesoduodenum is relatively long.

*Mesoduodenum is relatively long.

===Horse===

===Horse===

*Mesoduodenum is relatively short, so the duodenum is closely tethered in a constant position.

*Mesoduodenum is relatively short, so the duodenum is closely tethered in a constant position.

*The descending duodenum is attached to the base of the caecum.

*Descending duodenum is attached to the base of the caecum.

*The descending duodenum runs caudally beneath the liver to the caudal pole of the right kidney where it has it's caudal flexure to become the ascending duodenum.  

*Descending duodenum runs caudally beneath the liver to the caudal pole of the right kidney where it has it's caudal flexure to become the ascending duodenum.  

===Ruminant===

===Ruminant===

**It turns level with the tuber coxae.

**It turns level with the tuber coxae.

*The first part of the duodenum is attached to the [[Liver - Anatomy & Physiology|liver]] by the lesser omentum.

*The first part of the duodenum is attached to the [[Liver - Anatomy & Physiology|liver]] by the lesser omentum.

*The descending duodenum also provides attachment for the superficial and deep sheets of the greater omentum.

*Descending duodenum also provides attachment for the superficial and deep sheets of the greater omentum.

===Pig===

===Pig===