GI Organs

Question 1

where does the thoracic esophagus pierce the diaphragm?

Answer 1

T10

Question 2

where does the esophagus enter the stomach at the cardiac orifice?

Answer 2

T11

Question 3

where does the aorta pass thru the diaphragm?

Answer 3

T12

Question 4

where does the inferior vena cava pass thru the diaphragm?

Answer 4

T8

Question 5

sliding hiatal hernia

Answer 5

-esophageal hiatus of diaphragm enlarges or weakens

abdominal esophagus and parts of the stomach (cardia and sometimes fundus) herniate into the thorax

Question 6

paraesophageal hiatal hernia

Answer 6

i. A defect in diaphragm next to the esophageal hiatus
ii. Permits fundus of stomach to herniate (not usually the esophagus)
1. These occur next to the esophagus, so defect of diaphragm next to the esophagus
2. Fundus comes up next to esophagus

Question 7

where is stomach fixed?

Answer 7

i. Left end fixed at T10-11 at esophagus
ii. Right end fixed at L1-2 at duodenum
iii. Area b/w is variable—b/c stomach can get larger or smaller

Question 8

duodenum

Answer 8

1. C shaped
2. 10 inches long
3. located approximately at L1 to L4 vertebral bodies
4. starts at the pylorus of the stomach and ends at the duodenal jejunal junction
5. further subdivided into 4 parts:
   a. superior
   b. descending
   c. horizontal
   d. ascending
6. secondarily retroperitoneal

Question 9

superior duodenum

Answer 9

i. starts at pyloric sphincter
ii. about 2 inches long
iii. held in place by the hepatoduodenal ligament
iv. portal V, hepatic A, and bile duct are therefore posterior and superior to this part
v. duodenal bulb—widened area
vi. head of the pancreas is inferior to this part

Question 10

descending duodenum

Answer 10

i. about 3 inches long
ii. all secondarily retroperitoneal
iii. fundus of the gall bladder, right lobe of the liver, transverse colon are all anterior
iv. R kidney and ureter are posterior
v. Head of the pancreas is medial
vi. Bile and pancreatic ducts enter into the second part of the duodenum at the major duodenal papilla

Question 11

horizontal duodenum

Answer 11

i. Superior mesenteric A and V and the root of the mesentery cross the anterior surface of the 3rd part of the duodenum
ii. Head of the pancreas is superior
iii. Jejunum is anterior and inferior

Question 12

ascending diaphragm

Answer 12

i. Becomes intraperitoneal—not covered by parietal peritoneum
ii. Root of the mesentery and jejunum are anterior
iii. Left margin of the aorta and the medial border of the psoas muscle are posterior
iv. 4th part is held in place of the suspensory ligament (or muscle) of the duodenum (of Treitz)
1. suspensory ligament anchors the 4th part of the duodenum to the right crus of a diaphragm

Question 13

jejunum

Answer 13

a. 8-10 feet
b. 2/5 of free small intestine
c. simple vascular arcades, long vasa recta, more vascular
d. greater diameter, thicker, more plicae circularis

Question 14

plicae circularis

Answer 14

circular folds that go around jejunum

Question 15

ileum

Answer 15

a. 10-12 feet long
b. 3/5 of the free small intestine
c. has compound vascular arcades, shorter vasa recta, is less vascular
d. is smaller diameter, thinner wall
e. fewer plicae circularis

Question 16

meckel’s diverticulum

Answer 16

i. Most common congenital anomaly of the small intestine
ii. Arises from the antimesenteric border of the ileum
iii. Occurs in about 2% of the population
iv. About 2 feet from the ileocecal junction
v. Average about 2 inches long
vi. Remnant of the vitelline duct
vii. Clinically difficult to distinguish from appendicitis
viii. May contain other types of tissues

**usually 2 inches long, occurs 2 feet from ileocecal valve, in about 2% of the population, usually occurs in first 2 years of life, 2 types of epithelia–gastro and intestinal

Question 17

taenia coli

Answer 17

a. 3 bands of longitudinal muscle on the outside of the colon
i. converge at the root of the appendix
ii. produce houstrae that slow movement of feces

Question 18

epiploic appendages

Answer 18

i. tags of fat

ii. characteristic of large intestine

Question 19

cecum

Answer 19

i. no epiploic appendages
ii. blind “pouch” inferior to ileocecal orifice
iii. iliocolic valve is 2 folds that are not a true spincter
iv. ileal papilla is a cone like projection of the ileum into the cecum
v. opening for the appendix is inferior to the ileal papilla

Question 20

vermiform appendix

Answer 20

i. usually attached to the posteromedial part of the cecum
ii. located at the junction of 3 taenia coli
iii. 9-10 cm long and supported by a mesoappendix
iv. position is variable

Question 21

ascending colon

Answer 21

1. R colic feature—hepatic flexure
2. Secondarily retroperitoneal
   a. Except lowest part

Question 22

transverse colon

Answer 22

1. Left colic flexure (splenic flexure)

2. Intraperitoneal—transverse mesocolon

Question 23

descending colon

Answer 23

1. Secondarily retroperitoneal

Question 24

sigmoid colon

Answer 24

1. intraperitoneal

Question 25

rectum

Answer 25

i. b/w sigmoid colon and anal canal ii. anorectal line—line joining the tops of the anal columns iii. b/w the sigmoid colon and the anal canal iv. transverse rectal folds—superior/intermediate/inferior v. rectal ampula—dilated terminal part of the rectum vi. puborectalis muscle—defacation and relaxation of internal and external anal sphincters

Question 26

pectinate line above and below

Answer 26

1. above—simple columnar, superior rectal A, inferior hypogastric plexus 2. below—stratified squamous, middle and inferior rectal A, inferior rectal N

Question 27

parts of anal canal

Answer 27

i. Anal valves—at the base of the anal columns ii. anal sinuses—spaces b/w and at the inferior part of the anal columns iii. pectinate line—line joining the inferior end of the anal valves

Question 28

spleen--size, shape, location

Answer 28

i. left hypogastric region ii. parallels left ribs 9-11 iii. midaxillary line, b/w stomach and diaphragm iv. about size of hand v. normally not palpable below costal margin

Question 29

relations of spleen

Answer 29

i. diaphragm is posterior ii. stomach, left colic flexure, and tail of pancreas are anterior iii. the left kidney and phrenicocollic ligament are inferior

Question 30

peritoneal relationships of spleen

Answer 30

i. covered by peritoneum ii. develops from dorsal mesentery from mesoderm 1. gastrosplenic ligament 2. splenorenal ligament

Question 31

surfaces of the spleen

Answer 31

i. diaphragmatic 1. against diaphragm 2. smooth ii. visceral 1. hilum with gastrosplenic and splenorenal ligaments 2. there are colic, gastric, and renal impressions here

Question 32

pancreas location and peritoneal

Answer 32

a. mostly secondarily retroperitoneal | b. located at L1-2

Question 33

parts of the pancreas

Answer 33

i. head 1. with uncinate process 2. in the duodenal curve ii. body 1. triangular cross section iii. neck 1. constricted part b/w head and body iv. tail 1. some of tail is located in the splenorenal ligament 2. anterior to the hilus of the spleen

Question 34

relationships of the pancreas

Answer 34

i. superior mesenteric A and V are posterior to the neck ii. splenic V and A run horizontally superior to or posterior to the body iii. tail is against the spleen iv. IVC and aorta are posterior to the body v. Stomach is anterior to the spleen vi. Duodenum is superior, right and inferior to the head vii. Transverse colon lies anterior and inferior to the pancreas

Question 35

pancreatic duct system

Answer 35

i. Pancreas develops from a ventral bun in the ventral mesentery and a larger dorsal bud in the dorsal mesentery 1. Rotation of the stomach and the duodenum brings these buds together and the duct systems unite ii. The main or major pancreatic duct joins the bile duct and they enter the 2nd part of the duodenum together thru a common hepatopancreatic ampulla 1. This forms the major duodenal papilla iii. The accessory pancreatic duct enters the duodenum at the more superior minor duodenal papilla

Question 36

liver location and lobes

Answer 36

a. Most of the liver is in the RUQ b. Smaller left lobe in the LUQ 4 lobes of the liver i. left lobe ii. right love iii. caudate lobe iv. quadrate lobe

Question 37

falciform ligament of the liver

Answer 37

a. the falciform ligament is a double layer of peritoneum that connects liver to the anterior wall i. remnant of the obliterated umbilical vein

Question 38

liver surfaces and ligaments

Answer 38

i. diaphragmatic surface 1. smooth, fits concavity of diaphragm 2. peritoneum attaches the liver to the anterior body wall and the peritoneum splits to enclose a bare area a. bare area—anterior, posterior, left and right coronary ligament define this area i. includes the area where the IVC is posterior to the liver and the hepatic veins drain into it

Question 39

liver peritoneal attachments

Answer 39

i. falciform ligament with ligamentum teres | ii. lesser omentum with hepatoduodenal and hepatogastric ligaments

Question 40

location of gall bladder

Answer 40

in hepatic fossa

Question 41

fundus of gall bladder

Answer 41

i. lowest, widest part ii. contacts anterior abdominal wall at the midclavicular line, 9th or 10th costal cartilage iii. usually located on the transpyloric line

Question 42

extra hepatic bile passages of the gall bladder

Answer 42

i. together the R hepatic duct and L hepatic duct form the common hepatic duct ii. cystic duct iii. bile duct

Question 43

common bile duct

Answer 43

1. formed from the cystic and the common hepatic ducts 2. runs in the edge of the lesser omentum (hepatoduodenal ligament) 3. goes posterior and inferior to the 1st part of the duodenum, posterior to the head of the pancreas, enters the 2nd part of the duodenum with the pancreatic duct

Question 44

length of jejunum vs. ileum

Answer 44

8-10 ft vs. 10-12 ft

Question 45

arcades and vasa recta of jejunum vs. ileum

Answer 45

- simple and long | - complex and short

Question 46

overall blood supply of jejunum vs. ileum

Answer 46

- more vascular in jejunum | - less vascular in ileum

Question 47

plicae circularis of the jejunum vs. ileum

Answer 47

- more plicae circularis in jejunum | - less plicae circularis in ileum

Question 48

diameter of ileum vs. jejunum

Answer 48

- greater diameter in jejunum | - smaller diameter in ileum

Question 49

lymph above the pectinate line vs. below

Answer 49

- internal iliac LN above | - superficial inguinal LN below

Question 50

epithelium above vs. below the pectinate line

Answer 50

- simple columnar above | - stratified squamous below

Question 51

embryo of above vs. below pectinate line

Answer 51

- endoderm above | - ectoderm below

Question 52

artery supply above vs. below pectinate late

Answer 52

- superior rectal A. above | - middle and inferior rectal A. below

Question 53

veins above the pectinate line vs. below

Answer 53

- superior rectal V above | - middle and inferior rectal V below

Question 54

hemorrhoids above vs. below pectinate line

Answer 54

- internal above - not painful--visceral - external below - painful--somatic

Question 55

nerves above pectinate line vs. below

Answer 55

- inferior hypogastric plexus above | - inferior rectal N below