DSA: Organs of the GI Tract Flashcards
The thoracic esophagus pierces the diaphragm at _____ through the esophageal hiatus slightly left of midline
It turns sharply left to enter the stomach at the cardiac orifice about vertebra level _____
T10
T11
What are the 3 constrictions of the esophagus and what forms them?
Cervical constriction aka UES (crycopharyngeus m.)
Thoracic aka bronchoaortic constriction (L main bronchus + aortic arch)
Diaphragmatic constriction (R crus of diaphragm)
Describe para-esophageal hiatal hernia. Does the patient experience regurg?
Cardia of stomach is normal position, but peritoneum and fundus protrude anterior to esophagus
No regurgitation!
Describe sliding hiatal hernia. Does the patient experience regurg?
Esophagus, cardia, fundus protrude through hiatus
Yes there is regurgitation, worse with lying down
Which is more common, sliding or paraesophageal hiatal hernia?
Sliding hiatal hernia
In which quadrant(s) of the abdomen would you find the stomach?
Most commonly in right and left UQs
The left end of the stomach (fundus) is typically fixed at vertebral level ____, and the right end (pylorus) is fixed at _____
The area between is variable
T10-11; L1
Anterior relationships of stomach
Anterior abdominal wall
Diaphgram
L lobe of liver
Posterior relationships of stomach
Diaphragm Spleen (posterior and lateral) L suprarenal gland L upper kidney Pancreas Transverse colon (inferior and lateral) Transverse mesocolon Omental bursa (lesser sac)
The duodenum begins at the pylorus at the level of ____ and ends at the _______ flexure (junction) at L2
L1; duodenojejunal
The duodenum is subdivided into how many parts? Are the intraperitoneal or retroperitoneal?
4: superior, descending, horizontal/inferior, and ascending
First part (superior) is intraperitoneal; 2-4th are retroperitoneal
Which anatomical region of the duodenum is common for ulcerations and subsequent bleeding to occur?
Duodenal bulb
The hepatoduodenal ligament is associated with the ____ part of the duodenum and contains the portal triad.
What is contained in the portal triad?
1st
Portal vein
Hepatic artery
Bile duct
The head of what organ sits just inferior to the 1st part of the duodenum?
Pancreas
The bile duct and pancreatic ducts enter the ____ part of the duodenum at the _____ _____
2nd; duodenal papilla
A tumor in the head of the pancreas would likely block what important anatomical structure?
Common bile duct
Medial, anterior, and posterior relationships of the 2nd part of the duodenum
Medial: head of pancreas
Anterior: gallbladder (fundus), R lobe of liver, transverse colon
Posterior: right kidney and ureter
The superior mesenteric artery and vein, as well as the root of the mesentery, cross anteriorly over which part of the duodenum?
3rd part
Superior and anterior relationships of 3rd part of duodenum
Superior: head of pancreas
Anterior: jejunum
Vascular compression disorder referring to compression of left renal vein between superior mesenteric artery and aorta leading to renal venous HTN, rupture of veins in collecting system, and hematuria
Nutcracker syndrome
Posterior and anterior relationships of 4th part of duodenum
Posterior: left margin of aorta, inferior mesenteric vein, and psoas muscle
Anterior: root of mesentery and jejunum
The 4th part of the duodenum is held in place by what structure?
Suspensory ligament of duodenum = ligament of Treitz
Anchors 4th part ot right crus of diaphragm
In which abdominal quadrant would you find the jejunum
LUQ
In which quadrant would you find the ileum
RLQ
Both the jejunum and ileum are intraperitoneal, held in place by what?
The mesentery
Which makes up more of the small intestine, jejunum or ileum?
Ileum
Compare the vascular arcades, vasa recta, and general vascularization of the jejunum vs. the ileum
Jejunum = simple vascular arcades, long vasa recta, more vascular
Ileum = compound vascular arcades, shorter vasa recta, less vascular
Compare the diameter, thickenss, and plicae circularis in the jejunum vs. the ileum
Jejunum = greater diameter, thicker, more plicae circularis
Ileum = smaller diameter, thinner walls, fewer plicae circularis
Compare amount of lymphoid nodules (peyer patches) found in jejunum vs. ileum
Jejunum has few peyer’s patches while the ileum has many
What is the most common congenital anomaly of the small intestine? Which part of the small intestine is affected?
Meckel’s diverticulum, affecting the ileum (arises from the antimesenteric border of ileum) as a remnant of the vitelline duct
May contain other types of tissue like gastric, pancreatic, and/or jejunal
Meckel’s diverticulum is clinically difficult to distinguish from what other condition?
Appendicitis
What is the rule of 2’s referring to Meckel’s diverticulum?
Occurs in 1–2% of population
About 2 feet from ileocecal junction
Average of about 2 inches long
THE mesentery is what attaches the jejunum and ileum to the posterior body wall
Between the 2 layers of THE mesentery, are the _______ artery, lymph nodes, fat, and autonomic nerves
Superior mesenteric
THE mesentery crosses which major anatomical structures?
L2-L5 3rd and 4th part of duodenum Abdominal aorta IVC R ureter R psoas major R gonadal vessels
Name the regions of the large intestine
Cecum Appendix Ascending colon Right colic (hepatic) flexure Transverse colon Left colic (splenic) flexure Descending colon Sigmoid colon Rectum Anal canal
3 major features of large intestine
Taenia coli
Haustrae
Appendices (epiploicae)
_____ are 3 bands of longitudinal muscle on the outside of the colon that converge at the root of the appendix and produce sacculations called ________
Taenia coli; haustrae
What are the tags of fat on the large intestine called?
Appendices or epiploicae
T/F: the cecum tends to have abundant epiploic appendages
False, no epiploic appendages on the cecum!
Where is McBurney’s point? (Used to identify location of appendix)
1/3 of the way from the right ASIS on the spinoumbilical line
The cecum is a blind “pouch” inferior to the _____ orifice
The __________ is a cone-like projection of the ileum into the cecum, inferior to which is the opening for the ______
Ileocecal
Ileal papilla; appendix
The appendix is usually attached to the posterior-medial part of the cecum. It is located at the junction of 3 _______ and is supported by the _______
Taenia coli; mesoappendix
Are the 4 parts of the colon intraperitoneal or retroperitoneal? (What is each one?)
Ascending colon = secondarily retroperitoneal, except for the cecum
Transverse colon = intraperitoneal (transverse mesocolon)
Descending colon = secondarily retroperitoneal
Sigmoid colon = intraperitoneal (sigmoid mesocolon)
Which part of the colon is commonly affected by diverticulosis?
Sigmoid - most commonly on the mesenteric side of the 2 non-mesenteric teniae coli, where nutrient arteries perforate the muscle coat to reach the submucosa
What is volvulus of the sigmoid colon?
Rotation and twisting of the sigmoid colon resulting in obstruction of the lumen proximal to the twisted segment
Constipation may lead to fecal compaction, ischemia may result in necrosis
The rectum is found between the sigmoid colon and anal canal.
The _______ line is a line joining the tops of the anal columns, and the rectum is superior to it.
Anorectal
What are the transverse rectal folds
Folds that overlie the thickened parts of the circular muscles layer of the rectum (superior, intermediate, and inferior)
_____ = dilated terminal part of the rectum
Rectal ampulla
Where are the anal valves found
At the base of the anal columns
What are the anal sinuses
Spaces between and at the inferior part of the anal columns
______ line = a ling joining the inferior ends of the anal valves
Pectinate
The spleen is found in the left _____ region, paralleling ribs ____-____ at the midaxillary line, between the stomach and diaphragm
Hypochondriac; 9-11
T/F: the spleen is normally not palpable below the costal margin
True
The spleen is intraperitoneal, bound by what 2 ligaments?
Gastrosplenic
Splenorenal
Anterior, posterior, inferior, and medial relationships of the spleen
Anterior = stomach, tail of pancreas
Posterior = diaphragm
Inferior = left colic flexure
Medial = L kidney, phrenicocolic ligament
The pancreas is retroperitoneal except for the tail. It is located at vertebral level _____
L1-L2
4 parts of pancreas
Head with uncinate process located in duodenal curve
Neck
Body
Tail (intraperitoneal with splenorenal lig)
Where is the uncinate process of the pancreas n relation to the SMA and V?
Uncinated process is posterior to SMA and V
Where is the tail of the pancreas in relation to the hilum of the spleen?
Anterior to the hilum of the spleen
Anterior relationships of pancreas
Lesser sac and stomach
Posterior relationships of pancreas
Aorta and IVC Splenic v. Bile duct R crus of diaphragm L kidney and vessels L suprarenal gland SMA and SMV
Right, left, and inferior relationships of pancreas
Right = 2nd part of duodenum
Left = spleen
Inferior = 3rd part of duodenum
Describe pancreatic duct system including main duct, bile duct, and accessory duct
The main pancreatic duct joins the bile duct and they enter 2nd part of duodenum together through a common hepatopancreatic ampulla, this forms the major duodenal papilla (of Vater)
The accessory pancreatic duct may or may not be present - it enters the duodenum at the more superior minor duodenal papilla
Most of the liver is located in which quadrant?
RUQ
[the left lobe is located in the LUQ]
4 anatomic lobes of the liver
Left lobe
Right lobe
Caudate lobe
Quadrate lobe
What ligament divides the right and left hepatic lobes?
Falciform ligament
There are 4 anatomical lobes of the liver, but the liver can also be divided into functional lobes which are what are used clinically. What are these lobes based on?
Based on division of the portal triad and blood supply
For functional lobes of the liver, the right and left side are divided by the _____ line. Segment I is the _____ lobe. The other segments of the liver are either right or left.
Which segments of the functional liver are part of the left liver? The right?
Cantile; caudate
Left liver = segments II, III, and IV
Right liver = segments V, VI, VII, and VIII
The left liver contains segments II, III, and IV. The right liver contains segments V, VI, VII, and VIII. What are these functional segments called?
Left liver:
Segment II = left posterior lateral segment
Segment III = left anterior lateral segment
Segment IV = left medial segment
Right liver:
Segment V = right anterior medial segment
Segment VI = right anterior lateral segment
Segment VII = right posterior lateral segment
Segment VIII = right posterior medial segment
The _____ ligament (ventral mesentery) is a double layer of peritoneum that connects the liver to the anterior abdominal wall
Falciform
The falciform ligament contains the _________
Ligamentum teres (aka round ligament of the liver)
What are all the ligaments associated with the liver
Falciform (contains ligamentum teres)
Lesser omentum with hepatoduodenal ligament and hepatogastric ligaments
Coronary ligaments
R and L triangular ligaments
2 major surfaces of the liver
Diaphragmatic surface
Visceral surface
The diaphragmatic surface of the liver is smooth and fits the concavity of the diaphragm. It is covered by _____ peritoneum, except posteriorly in the bare area.
The bare area is defined by anterior, posterior, left, and right ______ ligaments. It includes an area where the _____ is posterior to the liver and the hepatic veins drain into it.
Visceral
Coronary; IVC
The visceral surface of the liver contains the ________, which is the transverse fissure between the caudate and quadrate lobes and transmits the portal triad
The visceral surface also contains the ______ (remnant of obliterated umbilical vein) in the edge of the falciform ligament, as well as the ______ which is the remnant of the obliterated ductus venosus and used to connect the umbilical vein with the IVC
The hepatic fossa is the space for the ______
Porta hepatis
Ligamentum teres; ligamentum venosum
Gallbladder
The gallbladder contacts the anterior abdominal wall at the ___ costal cartilage.
What are the 3 parts of the gallbladder?
9th
Fundus
Body
Neck
What are the extrahepatic bile passages
R hepatic duct L hepatic duct Common hepatic duct Cystic duct Bile duct
Describe the bile duct in relation to the duodenum and pancreas
Bile duct is posterior to the 1st part of duodenum and the head of the pancreas
It enters the 2nd part of the duodenum with the pancreatic duct
______ = gallstones, which are made up of ____ crystals
What are the 3 major places where gallstones may become lodged?
Cholelithiasis; cholesterol
Cystic duct, hepatic duct, hepatopancreatic ampulla
Describe possible result of gallstone blocking the cystic duct
Cholecystitis = inflammation of the gallbladder leading to biliary colic (intense spasmodic pain)
On PE, patient is ill-appearing, febrile, and tachycardic. True local parietal peritoneal inflammation will be aggravated by movement with voluntary and involuntary guarding.
Positive Murphy’s sign
Describe possible result of gallstone blocking the hepatopancreatic ampulla
This would block both the bile duct and the pancreatic duct
Bile may backup into pancreas and cause pancreatitis
Patient may also be jaundiced, which would not occur with cystic duct blockage
A patient with hx of gallstones presents with symptoms consistent with biliary colic and jaundice. You diagnose them with a gallstone blockage, where is the most likely location of the blockage?
Hepatopancreatic ampulla, because you would not become jaundiced with a blockage in the cystic duct
A ______ results when inflammation of the gallbladder leads to adhesions to other organs
Cholecystoenteric fistula
Which organs are most likely to be affected by cholecystoenteric fistula?
Superior duodenum
Transverse colon
If gallstones enter the intestine, where else might the gallstones cause a blockage?
Ileocecal junction
The esophagus enters the abdomen at the tip of the left ___ costal cartilage (vertebral level T10), and enters the stomach at the tip of the left ____ costal cartilage (vertebral level T11)
7th; 8th
Which part of the duodenum is the longest?
3rd part = 4 inches
[1st part is 2”, 2nd part is 3”, 4th part is 1”]
Duodenum:
First part is directed backward at _____ plane (vertebral level L1)
Second part is directed inferiorly to ______ plane (vertebral level L3)
Third part is directed horizontally to left side of vertebral level ____
Fourth part is directed superiorly to left side of vertebral level _____
Transpyloric
Subcostal
L3
L2
The root of mesentery of small intestine starts to the left of vertebral level ___ and ends at the _____ plane lateral to right side of linea semilunaris (vertebral level L5)
L2; transtubercular
The ileocecal valve is at the level of the _____ plane, lateral to the linea semilunaris at L5
Transtubercular
What are the planes used as reference points of the abdomen and their corresponding vertebral levels?
T9 = xiphisternal T11 L1 = transpyloric L3 = subcostal L5 = transtubercular S2 = interspinous Suprapubic
The cecum is at the level of the _____ plane, lateral to the right linea semilunaris
Transtubercular
The ascending colon starts at the ____ and ends at the hepatic flexure at the level of the ____ plane lateral to the right linea semilunaris
Cecum; transpyloric
The transverse colon starts at the hepatic flexure and ends at the ____ flexure at vertebral level ___, lateral to left linea semilunaris
Splenic; T12
The descending colon starts at the splenic flexure and descends to the iliac crest, lateral to left linea semilunaris. It ends medial to left linea semilunaris on ______ plane
Transtubercular
The sigmoid colon starts on the transtubercular plane and ends midline below the ____ plane
Interspinous
The upper border of the liver is in the _____ plane to the left linea semilunaris
The lower border of the liver goes from right costal margin to tip of right ____ costal cartilage to tip of left ___ costal cartilage to upper border
Xiphisternal
9th; 8th
The gallbaldder is located at the tip of ____ costal cartilage at the ____ plane
9th; transpyloric
