The Small Intestine. Flashcards
What are the sections of the small intestine?
The duodenum.
The jejunum.
The ileum.
What is the longest section of the small intestine?
The jejunum.
What is the shortest section of the small intestine?
The ileum.
Why are there more folds in the jejunum than in the ileum?
The wall of the jejunum is much softer than the wall of the ileum meaning that it is much more flexible.
Food from the stomach will be secreted into what area of the small intestine?
The duodenum.
The stomach opens into the duodenum on what side of the body?
On the right side of the body.
What is the most fixed part of the small intestine?
The duodenum.
What happens once food arrives into the duodenum?
A number of enzymes and chemicals arrive to help digest that food.
The enzymes that are secreted into the small intestine are released from what areas of the body?
The liver and the pancreas.
What delivers secretions from the liver to the duodenum?
The bile duct.
What delivers secretions from the pancreas to the duodenum?
The pancreatic duct.
Is it possible for 2 pancreatic ducts to be present in the duodenum?
Yes, these are the pancreatic duct and the accessory pancreatic duct.
Will all animals have an accessory pancreatic duct?
Some cats have an accessory pancreatic duct.
All dogs will have an accessory pancreatic duct.
What is the 1st section of the duodenum and where is it located relative to the median plane?
The descending duodenum.
It is located to the right of the median plane.
What additional features are found in the descending duodenum?
The duodenal flexure.
The opening of the pancreatic and bile ducts.
What name is given to the opening of the pancreatic and bile ducts?
The major duodenal papillae is the opening of the common bile duct.
The minor duodenal papillae is the opening of the pancreatic duct.
What is the 2nd section of the duodenum and where is it located relative to the median plane?
The transverse duodenum.
It crosses the median plane.
What part of the duodenum is also known as the caudal flexure of the duodenum?
The transverse duodenum.
What is the 3rd section of the duodenum and where is it located relative to the median plane?
The ascending duodenum.
It is located on the left side of the root of the mesentery/median plane.
What name is given to the connecting peritoneum that is associated with the duodenum
The meso-duodenum.
What is the role of the meso-duodenum?
It connects the duodenum to the body wall.
How is the duodenum connected to the colon of the large intestine?
Via the duodenal colic fold.
What feature marks the end of the duodenum?
The duodenal-jejunal flexure.
What structures are associated with the jejunum?
Jejunal loops which are a series of loops that increase the length of the jejunum.
The jejunum is mainly located in what part of the abdominal cavity?
On the floor, on the right side.
What part of the small intestine is commonly involved in hernias?
The jejunal loops.
Where does the mesentery of the jejunum run from and to?
It originates from the roof of the abdominal cavity at an area called the root of the mesentery and attaches to the jejunum.
The point of attachment to the roof of the abdominal cavity is quite narrow whereas the point of attachment to the organ is very wide.
What does the mesentery of the small intestine allow for?
For blood vessels and nerves to reach the jejunum.
It also prevents tangling of the jejunum.
The ileum of the small intestine is mainly present on what side of the median plane?
The right side.
What name is given to the location where the ileum opens into the colon of the large intestine?
The ileo-cecal-colic junction.
This is because the ileum, cecum and colon all meet at this location.
The ileum empties into what part of the large intestine?
It empty’s into the cecum at the ileo-colic opening.
What guards the ileo-colic opening?
The ileo-colic sphincter and by a papillae.
This prevents the back flow of ingesta from colon to ileum.
What does the ceco-colic opening allow for?
For ingesta to travel from the ceum to the colon and vice versa.
Is there any sphincter associated with the ceco-colic opening?
No.
Any ingesta that enters the cecum will be sent back into the colon via reverse peristaltic movements.
Why does the ileum open into the colon in the dog and cat?
As the cecum is not very functional.
Where does the jejunal mesentery originate from?
From the root of the mesentery which is attached to the roof of the abdominal cavity.
Where are the jejunal lymph nodes found?
In the root of the jejunal mesentery.
What name is given to the blood vessels that run through the jejunal mesentery?
Jejunal arcades.
These arteries will all anastamose with each other.
What blood vessels supply the small intestine?
Blood vessels called vasa recta which emerge from the jejunal arcades.
What blood vessels supply the pancreas and the duodenum?
The caudal pancreaticoduodenal artery.
The cranial pancreaticoduodenal artery.
Where does the caudal pancreaticoduodenal artery arise from?
From the cranial mesenteric artery.
Where does the cranial pancreaticoduodenal artery arise from?
From the gastroduodenal artery.
Do the 2 pancreaticoduodenal arteries anastamose with each other?
Yes.
