Overview of GI organs

Question 1

The digestive system includes what organs?

Answer 1

oral cavity

pharynx

esophagus

stomach

small intestine

large intestine

Question 2

What are the accessory digestive organs?

Answer 2

salivary glands

liver

gallbladder

pancreas

Question 3

Muscolofibrous tube which transports food bolus from oral cavity to esophagus

Answer 3

Pharynx

Question 4

Muscular tube connecting the pharynx to the stomach

Answer 4

esophagus

Question 5

Associated with the esophagus as it enters the abdominal cavity are anterior and posteriror vagal trunks. Describe the innervation of the anterior and posterior vagal trunks.

Answer 5

Anterior: consists of several smaller trunks whose fibers mainly come from the left vagus nerve

Posterior: consists of one single trunk whose fibers come from right vagus nerve

Question 6

What is the arterial supply of the esophagus?

Answer 6

• Esophageal branches from left gastric artery (celiac trunk)
• Esophageal branches from the left inferior phrenic artery (abdominal aorta)

Question 7

The esophagus is guarded at both ends by muscular sphincters. Descibe the features of the upper and lower esophageal spincter:

Answer 7

Upper: helps prevent the entrance of air during respiration and is a secondary line of defense against reflux

Lower: located at esophageal hiatus of the diaphragm, helps guard against gastro-esophageal reflux (primary)

Question 8

What are the 4 parts of the stomach?

Answer 8

Cardia/cardiac region- at the gastroesophageal junction

Fundus- dilated superolateral part

Body- Major part

Pyloric part- consists of wide pyloric antrum which leads into narrow pyloric canal

Question 9

What is the sphincter which surrounds the distal opening of the stomach?

Answer 9

Pyloric sphincter

Question 10

The stomach has 2 distinctive notches:

Answer 10

Cardial- lies within angle created by esophagus entering stomach

Angular incisure- bend on lesser curvature

Question 11

List the primary function of the small intestine and the 3 parts of it:

Answer 11

Primary site for nutrient absorption

Duodenum

Jejunum

Ileum

Question 12

This part of the small intestine forms a C-shaped loop around the head of the pancreas

Answer 12

Duodenum

Question 13

The duodenal cap is clinically important bc it is the most frequent location of what?

Answer 13

Peptic ulcers

Question 14

The duodenojejunal junction is suspended from the diaphragm by the suspensory muscle of the duodenum otherwise known as

Answer 14

Ligament of Treitz

Question 15

The dueodenojejunal junction is an important clinical landmark. Why?

Answer 15

It is the junction between upper and lower GI bleeds which have different clinical characteristics

Question 16

The jejunum is located in the

Answer 16

LUQ

Question 17

The ileum is located in the

Answer 17

RLQ

Question 18

What are 3 distinctive features which would allow one to distinguish between the jejunum and the ileum?

Answer 18

Jejunum: few arterial arcades, long vasa recta, and mesentary with little fat

Ileum: many arterial arcades, short vasa recta, and mesentary laden with fat

Question 19

The ileum opens into the large intestine at the ileocecal junction. Here there may be a remnant of embryonic development known as an

Answer 19

Ileal (Meckel’s) Diverticulum

Question 20

The large intestine is the site for

Answer 20

water reabsorption

Question 21

The large intestine is distinguished from the small intestine by

Answer 21

Omental appendicies- small fatty projections

Teniae coli- three bands of longitudinal smooth muscle

Haustra- sacculations

Question 22

The large intestine consists of what anatomical parts?

Answer 22

Cecum and appendix

Colon

• Ascending
• Transverse
• Descending
• Sigmoid

Rectum

Anal canal

Question 23

The cecum is continuous with the ascending colon and has what suspended from it?

Answer 23

Appendix

Question 24

The ileocecal junction and the cecum are clinically important because they can be the site of bowel obstruction via what 3 unique mechanisms?

Answer 24

Intussusception- telescoping of proximal segment of intestine into a more distal part

Volvulus- twisting of the intestine on itself

Gallstone ileus- gallstone blocking the ileocecal junction

Question 25

The appendix is an intestinal diverticulum which contains lymphoid tissue and has a short mesentary in the mesoappendix. However, it is variable in position which can complicate what diagnosis? What % of cases are misdiagnosed? What is the most common orientation?

Answer 25

Appendicitis 20% retrocecal

Question 26

Acute appendicitis requires emergency surgery as it could turn gangrenous or perforate resulting in what condition?

Answer 26

Peritonitis

Question 27

The ascending colon meets the transverse colon at what junction?

Answer 27

Right colic (hepatic) flexure

Question 28

The transverse colon meets the descending colon at what junction?

Answer 28

Left colic (splenic) flexure)

Question 29

If the sigmoid mesocolon is long the chances of what complication increase?

Answer 29

Volvulus -90% of cases occur in the sigmoid colon