GI Organs Flashcards
What planes can the ESO, stomach and pylorus be found at
The esophagus–> T10-11,
the stomach–> T11 and
the pylorus –> L1
How do we find the xiphisternal plane, which is at T__.
Xiphisternal plane (T9): find the linea alba and trace up to the sternum
How do we find the interspinous plane?
Interspinous plane (S2): find the ASIS bilaterally and draw a plane in between them
How do we find the transpyloric plane?
Transpyloric plane (L1): find the linea semilumaris and trace up to the costal margin OR [find the top of the sternum and the pubic bone, and draw a plane in the middle.
The esophagus is a 25cm long muscular tube.
What is its path? (3)
- Goes through the right crus of the diaphragm at T10
- enters the cardial orifice of the stomach at T11
- fits into the groove of the posterior liver
The _______ ligament attaches the esophagus to the diaphragm, which allows them to move independently of one another.
The phrenicoesophageal ligament attaches the esophagus to the diaphragm, which allows them to move independently of one
The esophagus has anterior and posterior vagal trunks. Where are they located?
The right vagus nerve contributes to a posterior vagal trunk that goes behind the esophagus.
The left vagus nerve contributes to an anterior vagal trunk that goes in front of the esophagus.
What are the constriction points of the esophagus?
- Cervical region: upper sphincter d/t the cricopharyngeus muscle.
- Thoracic area: one d/t aorta and one d/t left main bronchus.
- Diaphragmatic constriction point: esophageal hiatus, which is implicated in hiatal hernias.
The last two constriction point of the esophagus are the lower esophageal sphincter (LES) and the esophageal hiatus at T10. What pathology occurs here? (2)
Hiatal hernias: sliding and para esophageal
What is a paraesophogeal hiatal hernia?
- gastroesophageal junction (GEJ) is normal
- fundus of the stomach protrudes on the side of the esophagus into the thorax.
- less of a chance of GERD.
What is a sliding hiatal hernia, the most common??
- GEJ is displaced superioly, forming a bubble where the cardia produces, NOT THE FUNDUS
- “hourglass” shape
- More likely to get GERD
Angular incisure of the stomach?
Where the body meets the pylorus and becomes the pyloric canal
the stomach is not a fixed structure, meaning it can be very high or very low. What are the structures of the stomach from the esophagus to the duodenum? (5)
cardia, fundus, body, pyloric antrum, pyloric canal,
What attaches to the lesser and greater curvature of the stomach respectively?
Lesser is the superior border–> lesser omentum attaches
Greater curvature is the inferior border–> Greater omentum attaches here
Anteriorly, the stomach relates with:
- Diaphragm
- L lobe of liver
- Anterior abdominal wall
Inferolaterally, the stomach relates with:
lies on transverse colon
The stomach lies on the transverse colon and anteriorly touches the diaphragm, left lobe of the liver, and anterior abdominal wall. What does the stomach come in contact with posteriorly? (6)
- Diaphragm
- Spleen
- Left upper kidney/suprarenal gland
- Pancreas
- Lesser sac (omental bursa)
What are the 2 important ligaments of the stomach>
- Gastrohepatic L–> connects lesser curvature of the stomach to the liver
- Gastrocolic L–>greater curvature of stomach to the transverse colon
The _______ vessels run in the region of the gastrocolic ligament.
L and R gastroepiploic (gastro-omental) vessels
Gastric ulcers occur on the stomach, with 70% of cases d/t H. Pylori.
What is a complication?I
A gastric ulcer in the lesser curvature in the stomach can cause hemorrhage from the L gastric artery.
Duodenal (peptic) ulcers occur where?
How many cases relate to H. Pylori?
Occur: pylorus of the stomach or duodenum
90%
What is a complication of duodenal ulcers?
65% of duodenal ulcers (peptic ulcers) occur on the posterior wall of the first part of the duodenum. If this erodes the posterior wall significantly enough, it can eat through the gastroduodenal artery – which lies behind the posterior wall of the duodenum – and can cause hemorrhage.
Vagotomy is a treatment for _________
GERD
Why get a vagotomy?
- The parietal cells, located in the fundus and body of the stomach, produce HCl when stimulatedby the vagus nerve.
- Before proton pump inhibitors were made, people with gastric ulcers would have a vagotomy to stop parietal cells
- from making HCl.
Name the three types of vagotomies
- Truncal vagotomy
- Selective gastric vagotomy
- Selective proximal vagotomy
There are three types of vagotomies. What are they?
- Truncal vagotomy affects stomach AND other organs of the G.I. system as well.
- Selective Gastric vagotomy affects the entire stomach – but no other organ.
- Selective Proximal vagotomy affects only the region of the gastric ulcer is located.
How can we find L3 plane?
inferior costal margin at the mid-axillary line
What planes are the duodenum found?
Duodenum is located at L1-L3.
- 1st part–> L1 (transplyoric plane)
- 2nd part: L2-L3 on the right
- Third part is located: anterior to L3 (subcostal plane)
- Fourth part is located: left side of L3- superior to about L2
Parts of the duodenum
- A- Superior (1)- intraperitoneal
- B- Superior (1)- retroperitoneal
- C- Dscending duodenum (2)
- D. Horizontal duodenum (3)
- E. Ascending duodenum (4)
What would occur to vomit if there is an obstruction before the descending (2nd) part of the duodenum? (this is before the papilla)
there will be no bile in the vomit!
The duodenum begins at the pylorus and ends at the duodenojejunal junction.
The first (superior) part (at L1) is sometimes divided into two. why is this? What is the ligament that attaches here?
Because one part is intraperitoneal and the other is retroperitoneal.
The hepatoduodenal ligament (lesser omentum) attaches here
The 2nd (descending) part at L2/3 is important because it contains the minor and major duodenal papilla and hepatopancreatic ampulla.
What is released through these?
Bile from the gallbladder (common bile duct) and
pancreatic duct
Superior mesentaric A and V
relationship with duodenum
SMA/SMV pass in front of the horizontal duodenum (part 3)
Ligament of Trietz (suspensory m)
relationship with the duodenum
- -located in 4th part of the duodenum (ascending part) and separates the upper and lower GI
- Connects the duodenum–> R crus of the diaphram
The 3rd segement or horizontal duodenum is crossed over by a vein and artery. What are they? What passes behind the 3rd segment?
Superior mesenteric vein and artery. Which can compress the duodenum. The IVC and aorta pass behind it
The 4th segement or ascending is up due to the suspensory muscle. What flexure or junction occurs here?
Duodenojejunal flexure/junction occurs here and connects to the jejunum
If a patient has bright red blood in their stool, expect the bleed to come ____ the ligament of Treitz.
after
- *Jejunum**
- Majority is located in the ____
LUQ
- *Ileum**
- Majority is located in the ____
RLQ
The jejunum is located in the left upper quadrant and is intraperitoneal. The ileum is in the RLQ. How are they attached to the posterior wall?
Via a mesentary which starts from L2 (duodenojejunal junction) –> L5 (ileocecal junction)
How can one determine the difference between the jejunum and ileum from the
vasa recta,
arcades, and
circular folds (plicae circulares)?
- Jejunum: The vasa recta are long, with few large arcade loops and the plicae circulares are tighter and larger
- Ileum has short vasa recta, small loops, low/absent plicae circulares
Color, fat and number of peyers patches in Jejunum and Ileum
Jejunum
- Color- deep red because of greater vasculature
- Fat in mesentary- less
- Peyer’s patches- few
Ileum
- Color- pale pink because less vasculature
- Fat in mesentary- more
- Peyers patches- many
Usually asymptomatic, has a persistent vitelline/omphalomesenteric duct that can contain ectopic gastric or pancreatic tissue
Meckel Diverticulum
Most common congenital anomaly of GI tract that is a TRUE diverticulum
Meckels diverticulum
What occurs mostly in children, commonly at the ileocecal junction and is when proximal bowel segement is inside distal segement?
Intussusception… can cause bleeding at the ileocecal jxn
Most common pathologic lead point for intussusception is?
mecke;s diverticulum
Intussusception occurs when a segment of the proximal segment protrudes into a distal bowel segment, often at the ileocecal junction.
Looks like a _____ on ultrasound
target sign
What planes does the LI begin at?
- Large intestines begins at the ileocecal junction (L5: transtubercular plane)
- The lower edge of the ceceum is located at S2 (interspinous plane)
- -cecum is the out-pouch of the ascending colon
Parts of the LI
- ascending colon (includes the cecum and appendix),
- transverse colon,
- descending colon,
- sigmoid colon
- rectum.
What part of the LI are retroperitoneal?
- Ascending colon
- Descending colon
The colon is made up of the cecum, appendix, ascending, trasnverse, descending and sigmoid colon and begins at the ileocecal junction.
What is THE important external features?
The 3 tenia coli- large longitudinal bands with fat called epiploic appendices), which form haustra (bulges created by the contraction of the tenia coli that run the length of the large intestine)
What is the area that is tender to palpation when considering appendicitis and where can this area be found?
McBurney’s point
1/3 of the way between right ASIS and umbilicus in RLQ
The location of the appendix does very in many patients, so if need be, during surgery, you do what?
ou can follow the three tinea of the cecum –> root of the appendix.
The ascending colon is continuous with the transverse colon at the?
right colic (hepatic) flexure retroperitoneal
The transverse colon is suspended by the transverse mesocolon and is continuous with the descedning colon at the?
left colic (splenic) flexure
The descending colon is retroperitoneal and has a left paracolic gutter, continuous with?
sigmoid colon
The sigmoid colon is at S3, and is suspended by a long mesentary called the sigmoid mesocolon. Teniae coli terminate at the rectosigmoid junction. What is most commonly seen here in the elderly?
Volvulus
What is volvulus?
- Intestines (most often the sigmoid colon) rotates on itself, causing [constipation, ischemia and necrosis].
- Looks like a coffee bean.
In infants, ______ volvulus is most common. “Midgut” refers to the area of bowel from the end of the duodenum all the way to the last one third of the transverse colon.
In elderly, volvulus of the _____ is most common.
- midgut (from the end of the duodenum–> last 1/3 of the transverse colon
- sigmoid colon
The _____ is the largest abdominal organ and takes up most of the RUQ –
liver
- Top of the liver is roughly at the _________, and the bottom portion of the liver roughly follows the________________.
- How can we palpate the liver?
- xiphisternal plane
- subcostal line
- -when we breathe in, the liver moves down.
How would one take a liver biopsy?
Find the 10th rib, have patient exhale and hold to avoid collapsed lung
There are two ways of categorizing the liver into lobes – what are they?
anatomical lobes (have no functional signficance) and functional lobes
What are the left and right anatomic liver lobes separated by?
falciform L, which connects the liver–> anterior abdominal wall (From ventral mesentary)
There are also two “accessory” lobes of the liver. What are they?
1. Quadrate lobe (left hemi-liver)
2. Caudate lobe (functionally entirely seperate)
BOTH ARE ATTACHED TO THE RIGHT ANATOMIC LOBE
The round ligament of the liver is remnant of the umbilical vein while the ligamentum venosum is remnant of?
ductus venosus, which allowed blood to bypass the fetal liver
What ligament contains the proper hepatic artery, common bile duct, and the hepatic portal vein?
hepatoduodenal ligament, which is the anterior boundary of the epiploic foramen
Separating the liver into functional lobes is important for hepatic segmentoctomies. Each peice of that liver will receive its own HPA, HPV and LN, so it can be removed without affecting other. EXCEPT: caudate lobe; receives both portal bundles
How do we divide the functional lobes of the liver
right and left functional lobes by the “Cantlie line.”
This is an imaginary line drawn between the [diaphragm–> fundus of the GB]
What are the lobe segments in the left lateral division of the function liver?
II and III
What are the lobe segments in the left medial division?
IV and I on the back
*Note I is the caudate lobe which receives blood supply from both portal bundles
What are the lobe segements in the right medial division?
VIII and V
What are the lobe segements in the right lateral division?
VII and VI
Segments _______ are all a part of the right functional lobe.
Segments V, VI, VII, and VIII are all a part of the right functional lobe.
The gallbladder is a blind diverticulum attached to a common bile duct via cystic duct, which is between what segments of the liver?
IV and V
Neck- closest portion of the gallbladder to the cystic duct, which connects to the common bile duct (the common bile duct also accepts bile from the liver). That common bile duct meets with the pancreatic duct just before the duodenum and empties into the hepatopancreatic ampulla (aka ampulla of Vater). It meets with the second portion of the duodenum at the major duodenal papilla.
Recall that the hepatopancreatic ampulla is located in the second part of the duodenum, and is called the major duodenal papilla on the intraluminal side.
Potential obstruction points in the GB: if you have an obstruction, you will develop an infection _______ to the obstruction.
proximal
Potential obstruction points in the GB: if you have an obstruction, you will develop an infection proximal to the obstruction.
1. cystic duct
2. common bile duct
3. ampulla of vater
where would you get an infection if you have the obstructions in the 3 areas of the GB?
- Cystic duct: get infection or cholylethiasis of the GB
- Common bile duct: get an infection at the GB + liver or bile ducts
- Ampulla of Vater: get an infection in the GB, liver, bile duct + pancreas
