GI organs Part 1 Flashcards
What are the organs apart of the GI tract?
what are the associated GI tract organs?
organs apart of the GI tract:
- Esophagus
- small intestine
- colon
- rectum
- anal canal
organs associated with the GI tract:
- Spleen
- pancreas
- liver
- gall bladder
What are the 4 abdominal planes? where are they located? and what are they passing through?
Transpyloric plane: L1
-passes through the pyloric sphincter
Subcostal Plane: L2-3
-passes inferior to the costal margain
Transtubercular plane: L5
-passes through the iliac tubercles
Interspinous plane: S2
-passes through the ASIS
Components of the Esophagus
Passes through the esophageal hiatus at the level of T10
Enters the stomach at the cardiac orifice at level of T11
Cardiac notch seperates esophagus from fundus of stomach
Inferior esophageal sphincter is a physiologic not an anatomical sphincter because the diaphragm works as the sphincter
Where are the 3 constrictions of the esophagus?
Superiorly: level of cricoid cartilage at the juncture with the pharynx
Middle: crossed by aorta and left main bronchi
Inferiorly: diaphragmatic sphincter
what are the two different Hiatal Hernias?
Para-esophageal hiatal hernia:
- Cardia of stomach in normal position
- Peritoneum and fundus of stomach are anterior to esophugus and pinched in with the diaphragm
Sliding hiatal hernia:
-Esophagus, cardia of stomach and fundus of stomach protrude through esophageal hiatus up into the diaphragm
Characteristics, parts, and borders of the Stomach?
Volume is 2-4 liters
Location is the right and left upper quadrants
Left end fixed at level of T10-11
Right end fixed at level of L1
Parts: Cardia (connected to esophagus)
fundus (superior to cardiac orfice at the level of 5th rib), body (portion between fundus and pylorus),
antrum (wide portion of pylorus),
pylorus canal,
pylorus sphincter (normally closed. and regulates what goes into duodenum)
Inferior border: greater curvature where the greater omentum attaches
Superior border: lesser curvature where the lesser omentum attaches
Relationships of the stomach to the other organs?
Anterior: anterior abdominal wall, diaphragm, and the left lobe of the liver
Posterior: diaphragm, spleen, left suprarenal gland, left upper kidney, pancreas, transverse colon, transverse mesocolon, and omental bursa
Purpose of the Gastric Vagotomy? and the three types
Truncal Vgotomy: denervates nerve supply to all of stomach plus most of G.I. tract and liver
Proximal gastric vagotomy: denervates branches of vagus nerve going only to stomach
Selective Proximal vagotomy: specifically denervate area of stomach in which parietal cells are located (fundus and cardia)
-good for patients with patent gastric ulcers
Characteristics of the Duodenum and how many parts are their?
Begins at the pylorus and ends at the duodenojejunal junction (level of L2)
-length is 10”
1st part: intraperitoneal, 1: long and travels superior and to the right associated with the hepatoduodenal ligament
2nd part: retroperitoneal, 3-4”
3rd part: retro peritoneal 4”
4th part: retroperitoneal and 1” that joins with the jejunum (duodenojejunal junction or flexure)
what dumps into the 2nd part of the Duodenum?
Contains the hepatopancreatic ampulla and Major duodenal papilla which allow for the bile and pancreatic enzymes to enter the duodenum
Relations of 2nd part of the duodenum
Anterior:
- gallbladder
- right lobe of the liver
- transverse colon
- coiled of small intestine
Posterior:
- Hilum of right kidney
- right ureter
Lateral:
- right colic flexure
- ascending colon
- right lobe of the liver
Medial:
- Head of pancreas
- Bile and pancreatic ducts
Relations of the 3rd part of duodenum
Anteriorly:
- root of the mesentery of the small intestine
- superior mesenteric vessels contained within the mesentary
- coils of the jejunum
Posterioly:
- the right ureter
- the right psoas muscle
- inferior vena cava
- aorta
Superiorly:
-Head of the pancreas
Inferiorly:
-coils of jejunum
Relationships of the 4th part of the duodenum
Posteriorly:
- left crus of diaphragm
- left psoas major muscle
- left sympathetic trunk
- left renal vessels
- left gonadal vessels
- left supra renal vein
- inferior mesenteric vein
Right side:
-Uncinate process of pancreas
Left side:
-left kidney and ureter
superiorly:
-body of pancreas
what is the Ligament of Treitz
Suspensory muscle that attaches the 4th part of the duodenum to the posterior abdominal wall
-functions to widen the openings of this portion of the duodenum
anchors 4th part of the right crus of the diaphragm
can be torn during a MVA and high impact collision
Characteristics, location, and arterial supply of the Jejunum
Location: left upper quadrant
Intraperitoneal organ supported by the mesentery
Proximal 2/5s of the small intestine
Contains mucosal folds called plicae circulares that absorb nutrients
Mesenteric fat increases from proximal to distal (less here than in ileum)
supplied by (single) arterial arcades with long vasa recta
Characteristics, location, and arterial supply of the ileum
Location: right lower quadrant
intraperitoneal: supported by the mesentary
Distal 3/5s of the small intestine
Supplied by compound arterial arcades (layered) with short vasa recta
more fat here in mesentary
What is the mesentary and its relations and functions
Attaches the Jejunum and ileum to the posterior body wall
consists of 2 layers of peritoneum
Contains superior mesenteric arteries and veins, lymph nodes, fat and autonomic nerves
Relations: Crosses the 3rd/4th parts of the duodenum, aorta, IVC, right ureter, right psoas major and right gonadal artery and vein
what are the parts and the external characteristics of the large intestine?
Parts: Cecum, appendix, ascending colon, transverse colon, descending colon, and sigmoid colon
length is approximately 5 feet
begins at the ileocecal junction
External features:
- 3 tena coli (longitudinal bands of smooth muscle)
- Haustra (make up the segments)
- Appendices epiploicae (store fat)
Characteristics of the Cecum and function of the appendix
Cecum: blind pouch (intraperitoneal) continuous with ileum and ascending colon
Appendix: attache to posterior medial part of cecum and supported by mesoappendix
- position is variable
- contains several lymphoid nodules important part of the immune system
what are the two flexures of the colon?
Hepatic flexure (right side) -right colic flexure
Splenic flexure(left side -left colic flexure
Signs of acute appendicitis
-low grade fever
-coughing causes pain (dunpys sign)
-tenderness at mcburneys point
-pain felt during palpation of the left lower quadrant (rosvings sign)
-
What is an Ileal Diverticulum?
Ileal (meckels) diverticulum
- occurs in 1 to 2 percent of population
- located 50 cm from iliocecal junction
- may be free or attached to the umbilicus
- protrusion of the illeum that becomes inflamed and mimicks pain produced by acute appendicitis
Characteristics of the Cecum
Contains ileal papilla (cone like projection of ileum)
-ileocecal valve regulates passage of ileal contents into the cecum
Characteristics of the Transverse Colon
Intraperitoneal with length of 10-14”
suspended by the transverse mesocolon
Continuous with descending colon at the right (splenic) flexure
Characteristics of the Descending colon
Retroperitoneal
left paracolic gutter lateral to descending colon
continuous with sigmoid colon
Characteristics of the sigmoid Colon
Length is approximately 12”
-Continuous with the rectum at the level of S3
Suspended by the sigmoid mesocolon
Characteristics of the Ascending Colon
Length 8-10”
Continuous with cecum and transverse colon at right (hepatic) colic flexure
Retroperitoneal organ adjacent to right paracolic gutter
What is Volvulus of sigmoid colon?
- Involves rotation and twisting of the mobile loop of the sigmoid colon and sigmoid mesocolon
- results in obstruction of the lumen of the descending colon and any part of sigmoid colon proximal to the twisted segment
- Obstipation and ischemia of looped portion of sigmoid colon may result
- Bottom line is an acute surgical emergency
Rectum Characteristics?
Defined as both retroperitoneal and subperitoneal
located in pelvic cavity
length is approximately 5”
Contains 3 transverse rectal folds
-superior, middle and inferior
Continuous with anal canal
Characteristics of the Anal Canal and what are the two sphincters and what are they comprised of and innervated by?
Length is approximately 1 and a half inches
Contains anal columns, anal valves and anal sinuses
2 anal sphincters:
- Internal anal sphincter comprised of smooth muscle and is involuntary innervated by the parasympathetic ns
- External anal sphincter comprised of skeletal muscle and is voluntarily innervated
Pectinate line distinguishes the change of these two points
-located at the inferior ends of the anal valves
External opening is known as the anus!
Characteristics of the spleen
Location: left upper quadrant or left hypochondriac region lying parallel to left ribs 9-11 along the midaxillary line between the stomach and the diaphram
Intraperitoneal organ
Attached to both the gastrosplenic and splenorenal ligaments
-Most fragile and most susceptible to injury
Relationships of the spleen
Diaphragmatic surface
-duaphragm
Visceral surface:
Anterior: fundus of stomach
Posterior: left suprarenal gland and kidney
Inferiorly: tail of pancreas and left colic flexure
-will come in contact with the hilum of the spleen
Pancreas location and the 5 parts?
Location at level of L1-L2
Parts:
- Head: lies in curvature of the duodenum
- Neck: indistinct and joins head to body and overlies the superior mesenteric a
- Body
- Tail: located within the splenorenal ligament, its tip is adjacent to hilum of spleen
- Uncinate process- adjacent to head and superior to third part of duodenum
Ducts of the Pancreas
Main Pancreatic duct:
- begins in the tail and courses to the head
- usually joined by accessory duct in the head
- contains the sphincter of the main pancreatic duct which prevents bile entering the pancreas
- joins common bile duct
Accessory pancreatic duct
-accessory pancreatic duct may have a separate opening into the duodenum at the minor duodenal papilla
what is created when the pancreatic duct and the common bile duct come together?
Create the hepatopancreatic ampulla
- this is associated with the sphincter of Oddi and major duodenal papilla
- allowing for entry into the duodenum
Relationships of the Pancreas
Anterior: Lesser sac (omental bursa) and stomach
Posterior: aorta, IVC, splenic v, common bile duct, right crus of diaphragm, left kidney and vessels, left suprarenal gland, superior mesenteric artery and vein
right: duodenum (2nd part)
left: spleen
InferiorL duodenum (3rd part)
Location, size, and surfaces of the Liver
Size: 5% of body weight in infants, 2% body weight in adults
Location: upper right quadrant or epigastric and right hypochondriac regions
-left lobe located in left upper quadrant
Surfaces:
-Diaphragmatic surface: conforms to concavity of diaphram covered by peritoneum except where it is in direct contact with the diaphragm, IVC is in direct contact with this surface
-Visceral surface: covered with peritoneum except where gall bladder and porta hepatis are located. Transmits porta hepatis
What is part of the Porta Hepatis?
- Hepatic portal Vein
- Proper hepatic artery
- Common hepatic duct
- nerve plexus
- lymphatic vessels
What are the two fissures of the Liver and what is contained in them?
Left sagital fissure:
- on visceral surface
- contains ligamentum teres (obliterated umbilical vein)
Right sagital fissure:
- on visceral surface
- contains gall bladder and IVC
What are the anatomical Liver lobes
Right lobe: Larger than left and includes the quadrate and caudate lobes which are seperated by the porta hepatis
Left lobe: smaller than right lobe
-seperated from right lobe by the falciform ligament
Caudate lobe: between IVC and calciform ligament
Quadrate lobe: between gall bladder and falciform ligament
Liver and the Functional lobes
Functional lobes are based on the division of the portal triad and blood supply
Right and left liver divided by the Cantlie line
Right liver:
- V right anterior medial segment
- VI right anterior lateral segment
- VII right posterior lateral segment
- VIII right posterior medial segment
Left liver:
- I caudate lobe
- II Left posterior lateral segment
- III left anterior lateral segment
- IV left medial segment
what surrounds the bare area of the liver
the Coronary ligaments surround the reflection of visceral peritoneum from liver to the respiratory diaphragm
What are the two ligments of the lesser omentum
Hepatogastric ligament
-passes from porta hepatis to lesser curvature of stomach
Hepatoduodenal ligament
- passes from porta hepatis to duodenum (1st part)
- contains proper hepatic a, hepatic portal v, common ble duct, lymphatic vessels and hepatic nerves
Cirrhosis of liver
Alcoholic cirrhosis most common type of characterized by hepatomegaly and hobnail apperance of the liver surface resulting from fatty changes and fibrosis
genetic component in males related to amount of hair on chest
flow of Bile in the Biliary system
from the liver goes into either the right or left hepatic ducts of liver
these converge to make the common hepatic duct where it will join with the cystic duct coming from the Gallbladder
-bile can go up to gallbladder here to be stored
the common hepatic duct and cystic duct will meat together to make the Bile duct
the bile duct travels down through its sphincter to meet with the pancreatic duct to make the hepatopancreatic ampulla
what are Gall stones and who are at common risk
Cholelithiasis
- made of cholesterol crystals
- can be lodged throughout the biliary tree
- cause a back up of bile that can cause pancreatitis
Common risk factors are the 4 Fs
- Female
- Fat (obese)
- Fortys
- Fertile (pre-menopausal)
- american indians and mexican americas are at higher risk
Obstructive jaundice
stones inside the common bile duct and biliary tree can lead to Jaundice due to the inabillity to get rid of coagulated bilirubin
-exits through the bile duct
