Small and Large intestine Flashcards
What is the longest part of the gastrointestinal tract?
The small intestine
Where does the small intestine begin and end?
Begins from the pyloric orifice to the ileocecal fold
What is the first part of the small intestine and where is it located?
The duodenum
Located adjacent to the head of the pancreas
The duodenum is mainly retroperitoneal with exception to?
The first part of the duodenum which is connected to the liver by the hepatoduodenal ligament
The duodenum is connected to the liver by which peritoneal ligament?
Hepatoduodenal ligament
List the four divisions of the duodenum
Superior part
Descending part
Inferior part
Ascending part
Describe how the superior part of the duodenum extends, with relation to nearby structures.
Extends from the pyloric orifice of the stomach to the neck of the gallbladder
Then passes anteriorly to the bile duct, gastroduodenal artery, portal vein, and inferior vena cava
Which verteberal level is the duodenum located near?
Located to the right of L1
Describe how the descending part of the duodenum extends, with relation to nearby structures.
Extends from the neck of the gallbladder to the lower border of vertebra LIII.
Its anterior surface is crossed by the transverse colon.
Posterior to it is the right kidney
Medial to it is the head of the pancreas.
The descending part of the duodenum has two major structures within them. List them.
Major duodenal papilla
Minor duodenal papilla
Describe how the inferior part of the duodenum extends, with relation to nearby structures.
The inferior part crosses the inferior vena cava, the aorta, and the vertebral column anteriorly
It crosses the superior mesenteric artery and vein inferiorly
Describe how the ascending part of the duodenum extends, with relation to nearby structures.
Passes upward on, or to the left of, the aorta to approximately the upper border of vertebra LII and terminates at the duodenojejunal flexure
The common entrance for the bile and pancreatic duct is known as?
The major duodenal papilla
The entrance for the accesory pancreatic duct to the duodenum is known as?
The minor duodenal papilla
This duodenojejunal flexure is surrounded by a fold of peritoneum containing muscle fibers called?
Suspensory muscle (ligament) of duodenum (ligament of Treitz).
Describe the arterial supply of the duodenum
Gastroduodenal artery,
Supraduodenal artery from the gastroduodenal artery
Anterior superior pancreaticoduodenal artery (from the gastroduodenal artery),
Posterior superior pancreaticoduodenal artery (from the gastroduodenal artery),
Anterior inferior pancreaticoduodenal artery (from the inferior pancreaticoduodenal artery—a branch of the superior mesenteric artery),
Posterior inferior pancreaticoduodenal artery (from the inferior pancreaticoduodenal artery—a branch of the superior mesenteric artery), and
Superior mesenteric artery.
The last two sections of the small intestine are made up of?
The jejunum
The ileum
Describe the differences in the characteristics of the jejunum in relation to the ileum.
Jejunum is larger in diameter and has a thicker wall
Has more mucosal folds known as plicae circulares
Have less prominent arterial arcades and longer vasa recta (straight arteries)
How much of the small intestine is occupied by the jejunum and ileum?
Jejunum makes up 2/5ths of the small intestine
Ileum makes up 3/5ths of the small intestine
Describe the differences in the characteristics of the ileum in relation to the jejunum.
Ileum has thinner walls
Have less plicarae circulares
Have shorter vasa recta and longer arterial arcades
Has more mesenteric fat
The ileum joins the large intestine between which two structures?
the cecum and ascending colon at the ileocecal fold
Describe the ileal supply of the artery
The ileal arteries (branch from the superior mesenteric artery)
Ileal branch of the ileocolic artery
What are the main components of the large intestine?
Cecum
Appendix
Ascending colon
Transverse colon
Descending colon
Sigmoidal colon
Rectum
Anal canal
The bend between the ascending and transverse colon are known as?
The right hepatic flexure
The bend between the transverse and descending colon is known as?
The left hepatic flexure
What suspends the appendix?
The mesoappendix (attached from the ileum to the apendix)
Describe the location of the appendix in relation to other nearby structures
Located posteriomedially of the cecum
Inferior to the end of the ileum
What does the mesoapendix supply to the appendix?
Contains the appendicular vessels
What are the varying positions of the appendix?
Posterior to the cecum or the lower ascending colon, or both, in a retrocecal or retrocolic position;
Suspended over the pelvic brim in a pelvic or descending position.
Below the cecum in a subcecal location
Anterior to the terminal ileum in a pre-ileal position
Posterior to the terminal ileum in a postileal position.
McBurney’s point can be used to determine the location of the appendinx. State its location.
One-third of the distance laterally on a line drawn from the umbilicus to the right anterior superior iliac spine
What are the 3 main arteries that supply the cecum and appendix?
The anterior cecal artery from the ileocolic artery (from the superior mesenteric artery),
The posterior cecal artery from the ileocolic artery (from the superior mesenteric artery), and
The appendicular artery from the ileocolic artery (from the superior mesenteric artery
What are the divisions of the colon?
Ascending
Transverse
Descending
Sigmoid
Which parts of the colon are introperitoneal and retroperitoneal?
Ascending and Descending = Retroperitoneal
Transverse and sigmoid = Intraperitoneal
What is the junction of the ascending and transverse colon?
The right colic felxure
Where does the right colic flexure lie in relation to other structures?
Inferior to the right lobe of the liver
The junction between the transverse and descending flexure is known as?
The left colic flexure?
Where does the right colic flexure lie in relation to other structures?
Lies inferior to the spleen
The left colic flexure is held to the diaphragm and spleen by?
The phrenicolic ligament (diaphragm)
The splenocolic ligament (spleen)
Describe the origin and extension of the sigmoid.
Is continous with the descending colon and starts above the pelvic inlet.
It extends to the level of S3 and is continous with the rectum.
What 3 main arteries supply the transverse colon?
The right colic artery from the superior mesenteric artery,
The middle colic artery from the superior mesenteric artery
The left colic artery from the inferior mesenteric artery.
