Duodenum, Pancreas, and Intestines (lecture) Flashcards
What part of the duodenum is at risk from an anterior midline stab wound and what major artery would be at risk?
- 3rd part
- SMA would probably be severed as well because it overlies the 3rd part of the duodenum
Which part of the duodenum receives the combined pancreatic and bile ducts?
part 2
What structures could be damaged by pressure of the SMA pressing down on them?
- Left Renal v.
- 3rd part of the duodenum
What are some symptoms of Nutcracker syndrome?
- L Renal vein gets entraped by the SMA
- Often this presents with pain in the left testicle
What holds up the gooseneck at the duodenojejunal junction?
- Suspensory ligament
Describe the parameters of the suspensory ligament.
- Starts from RIGHT CRUS of diaphragm at esophageal hiatus (T10)
- Runs from L to R across aorta to end at dudodenojejunal junction 1 in to the LEFT of midline
T or F: the common bile duct runs posterior to the 1st part of the duodenum.
True
Describe the appearance of the 1st part of the duodenum on a radiograph.
Smooth
What structure marks the junction of the midgut and foregut?
Duodenal Papilla
What is the blood supply to the GI proximal and distal to the duodenal papilla?
- Foregut - celiac trunk
- Midgut - SMA
In which mesentery can the tail of the pancreas be found?
- Lienorenal fold
- This means the tail is the only part of the pancreas that intraperitoneal
What artery and vein lie deep to the neck of the pancreas?
SMA and SMV
What pancreatic structure is defined as lying behind the SMA and SMV?
Uncinate process
What would be the primary concern with a perforated ulcer in the posterior wall of the stomach?
You would worry about the pancreas being exposed to erosive secretions
In an attempt to tie off the cystic duct a surgeon accidentally closes off a nearby duct in the epiploic foramen causing jaundice in the patient. What duct was closed off?
- common bile duct
While trying to tie off the cystic duct the surgeon pierces a vein located posteriorly. What vein was hit?
- IVC
What part of the small intestine is located more superiorly and to the left of the midline?
Jejunum
What part of the small intestine is located more inferiorly and to the right of the midline?
Ileum
Where does the root of the mesentary begin and end?
- Begins at duodenojejunal junction 1 in to the left of the midline at or below the transpyloric plane
- Ends at McBurney’s pt. which is 1/3 of the way up on the line from the ASIS to the umbilicus
Which contains more fat, the mesentery of the jejunum or that of the ileum?
Jejunum contains less fat gives it some translucent windows
Where would you expect to see a greater amount of arterial arches between the jejunum and ileum?
the ileum has many more arches
What three external features distinguish the colon from the other parts of the gut tube?
- Tenia Coli - long bands of longitudinal muscle running the length of the intestine (there are 3 of these)
- Haustra - pouches caused by widely spaced circular bands of muscle
- Epiploic appendices - small fat pouches found along the colon
Where would you expect tenderness if a patient has appendicitis?
McBurney’s pt. which is 1/3 of the way up on the line from the ASIS to the umbilicus
What happens if you loose blood supply in your colon?
You die
What are the branches of the SMA?
- Inferior pancreaticoduodenal aa.
- Intestinal aa. (jejunal and ileal aa.)
- Middle Colic a.
- Right colic a.
- Ileocolic a.
What are the branches of the IMA?
- Left Colic a.
- Sigmoidal aa.
- Superior Rectal a.
T or F: both the celiac and SMA arise from the aorta above the transpyloric line
True
What anatomical landmark approximates the change in parasympathetic innervation in the gut tube?
Splenic flexure
- This marks the line between midgut (vagus n.) and hindgut (S2-S4)
What two arteries form the marginal a. and where do they anastomose?
SMA and IMA
- they come together about 2/3 of the way down the transverse colon just before the splenic flexure
You notice that a patient has a decrease in muscle tone in the colon as it passes anterior to the spleen. What could this be indicative of?
pathology in the S2-S4 parasympathetic nn.
What courses along the root of the mesentery proper?
SMA
In relation to surface anatomy, where does the IMA branch out from the aorta?
3/4 of an inch above the umbilicus
In relation to surface anatomy, where does the aorta bifurcate into the R and L common iliac aa?
3/4 of an inch below the umbilicus
What two veins come together to make the portal vein and where does this occur?
- Superior mesenteric vein and splenic vein
- occurs in the pyloric plane just posterior to the neck of the pancreas
What causes portal hypertension?
increased vascular resistance through the liver
What are some common indicators of portal hypertension?
engorgement of portal-caval anastomoses and ascites
T or F: portal venous pressure typically = caval venous pressure
True
What are some common causes of portal hypertension?
- Cancer
2. Cirrhosis of the liver
Where does caval blood go?
RA
Where does portal blood go?
The liver
What are 3 common places where we see portal-caval anastomoses occur?
- Esophageal
- Across the stomach
- In Anus
Describe how esophageal portal-caval anastomoses occur and their associated risk.
- Esophageal branch of L. gastric VIEN (portal) connects with one of the VIENs (caval) from the upper 2/3 of the esophagus (that run into azygous)
- These can burst and kill you
Explain why a person may have portal-caval anastomoses across their stomach.
- Veins surrounding the obliterated umbilical vein (ligamentum teres) (portal) start to drain into the superior and inferior epigastic veins (caval) causing them to enlarge and become visible in some cases
- Not that dangerous
Explain why a personal may have portal-caval anastomoses in dat ass hole.
- Superior rectal vein (portal) anastomoses with middle and inferior rectal veins (caval)
- NO pain, NOT dangerous
- usually recognized when people have bright red stuff in the stool
