Lec 34 Upper Gi Tract

Front 1

What does the Upper GI Tract consist of (function and structures)?

Back 1

Upper GI Tract= swallowing and digesion
Mouth
Pharynx
Esophagus
Stomach

Front 2

What does the Lower GI tract consist of (function and structures)?

Back 2

Lower GI tract= absorption
Small Intestines
Large intestines

Front 3

What is the junction of the upper and lower GI demarcated by (in clinical textbooks)?

Back 3

The junction of the duodenum and the jejunum (duodenojejunal flexure).

Front 4

Is the gastroesophageal (cardiac) sphincter a physiological or anatomical sphincter?

Back 4

Physiological.

Front 5

What is the function of the gastroesophageal sphincter?

Back 5

To prevent reflux of gastric contents into the esophagus.

Front 6

Esophageal veins form a submucosal venous plexus. Where does this occur?

Back 6

At the distal end of the esophagus.

Front 7

Where do esophageal veins drain?

Back 7

Into tributaries of the azygos system and the portal vein.
NOTE: this is the site of anastomosis between the portal (portal vein) and caval (azygos vein to SVC) circulations.

Front 8

What are esophageal varices?

Back 8

Enlarged esophageal veins in the submucosa of the esophagus.

Front 9

What causes esophageal varices?

Back 9

Increased pressure in the portal vein (portal hypertension)

Front 10

What is the result of ruptured esophageal varices?

Back 10

Massive bleeding and vomiting of blood (hematemesis).

Front 11

What is Barrett's esophagus associated with?

Back 11

1. GERD (gastroesophageal refluc disease).
2. Esophageal cancer (adenocarcinoma)- this is relatively rare and deadly. The pre-cancerous form is asymptomatic.

Front 12

What occurs in patients with Barrett's esophagus?

Back 12

The esophageal lining epithelium is replaced by tissue similar to that found in the stomach (intestinal metaplasia)

Front 13

What occurs in patients with Achalasia?

Back 13

1. The ability of the esophagus to propel food from the mouth to the stomach is lost.
2. The valve mechanism (sphincter) at the lower end of the esophagus fails to relax to allow the food into the stomach.

Front 14

Most cases of Achalasia occur between ages __ and __?

Back 14

20, 40

Front 15

What do patients with achalasia typically experience (major symptom)?

Back 15

Dysphagia- which becomes worse during emptional stress or rapid eating.

Front 16

What are the results of achalasia? ( there are 6)

Back 16

1. Obstruction of the distal esophagus with proximal dilation
2. Incomplete relaxation of the lower esophageal sphincter
3. Megaesophagus= dilation of the esophagus beginning at the upper 1/3, eventually involving the entire length
4. Failure of normal peristalsis in the smooth muscle portion
5. Lack or paucity of ganglion cells in Auerbach's plexus.
6. Carcinoma develops in 7%

Front 17

Name the 4 parts of the stomach

Back 17

1. Cardia
2. Fundus- at cardiac notch
3. Body
4. Pyloric part- antrum and canal. The pyloric canal contains the pyloric sphincter.

Front 18

Name the two curvatures of the stomach.

Back 18

1. Greater curvature
2. Lesser curvature.

Front 19

What are the 3 ligaments of the greater omentum?

Back 19

1. Gastrocolic ligament (stomach- transverse colon)
2. Gastrophrenic ligament(stomach-diaphragm)
3. Gastrosplenic ligament

Front 20

What are the 2 ligaments of the lesser omentum?

Back 20

1. Hepatogastric ligament
2. Hepatoduodenal ligament (supports the duodenum but NOT the stomach)

Front 21

What are the 5 internal features of the stomach?

Back 21

1. Cardiac orifice
2. Rugae (gastric folds/ridges)
3. Gastric mucosa (gastric pits lead to gastric glands in the lamina propria)
4. Gastric canal
5. Pyloric orifice

Front 22

How many muscular layers are present in the stomach and what are they?

Back 22

There are 3 layers unlike the rest of the GI tract with 2 layers.
1. Outer longitudinal
2. Middle circular (in pylorus, normally thickened to form the pyloric sphincter)
3. Inner oblique

Front 23

What demarcates the junction of the stomach and duodenum?

Back 23

The pyloric sphincter

Front 24

In the stomach, what marks the junction of the body and pyloric part?

Back 24

The angular incisure/notch.

Front 25

What is pyloric stenosis?
(three characteristics)

Back 25

1. Marked thickening of the pyloric sphincter.
2. Severe narrowing of the pyloric canal
3. Obstruction to passage of food

Front 26

What are the 3 symptoms of pyloric stenosis (in adults)?

Back 26

1. Visible peristalsis
2. Dehydration
3. Weight loss

Front 27

What are the 2 symptoms of pyloric stenosis in infants?

Back 27

1. Abdominal distension
2. Projectile vomiting (vomitus without bile)

Front 28

Is pyloric stenosis more common in males or females?

Back 28

Males!
1:150 males
1:750 females

Front 29

What are the contents of the stomach bed (7)?

Back 29

1. Pancreas- body/tail
2. Left kidney
3. Spleen
4. Diaphragm
5. Left suprarenal gland
6. Transverse mesocolon
7. Omental bursa (lesser sac)

Front 30

What causes gastic ulcers?

Back 30

*H. pylori weakens the protective mucous coating of the stomach and duodenum, this allows acid to get through to the mucosa.
* Both the acid and bacteria irritate the mucose causing an ulcer.

Front 31

How is H. Pylori able to survive in the stomach?

Back 31

1. It secretes enzymes that neutralize the acid
2. Its spiral shape helps it burrow through the mucosa.

Front 32

Where are gastric ulcers most likely to occur?

Back 32

Near the pyloric part of the stomach toward the lesser curvature.

Front 33

How do chronic gastric ulcers typically present?

Back 33

As epigastric pain.

Front 34

What is the result of a posterior perforation of a gastric ulcer? (there are two)

Back 34

1. It can secondarily involve structures in the stomach bed especially the pancreas
2. It can involve the splenic artery resulting in massive intra-abdominal bleeding.

Front 35

What are the parts of the duodenum?

Back 35

1. 1st part- superior
2. 2nd part- descending
3. 3rd part- inferior/horizontal
4. 4th part- ascending

Front 36

What could be affected by a posterior perforation of a duodenal ulcer?

Back 36

Gastroduodenal artery- resultinig in hemorrhage.

Front 37

What is present in the 1st part of the duodenum (LV1) ?

Back 37

1. Liver
2. Gallbladder (could pass a stone into the duodenum or transverse colon through a fistula).
3. Gastroduodenal artery (passes posteriorly)

Front 38

Where do duodenal ulcers typically occur?

Back 38

In the proximal half of the first part od the duodenum (duodenal cap or ampulla)

Front 39

What is the result of an anterior perforation of a duodenal ulcer?

Back 39

Peritonitis.

Front 40

What is present in the second part od the duodenum (LV1-LV3)?

Back 40

1. Transverse colon
2. Anteriorly: Common bile duct and major pancreatic duct
3. Posteriorly: Head of the pancreas

Front 41

What is in the 3rd part of the duodenum (LV3)?

Back 41

1. Superior mesenteric artery
2. Superior mesenteric vein
3. Head of the pancreas
4. Uncinate process of the pancreas

Front 42

What is superior mesenteric artery syndrome?

Back 42

The superior mesenteric artery and vein pass anterior to the duodenum and compress it against the aorta causing obstruction.

Front 43

What is in the 4th part of the duodenum (LV2-LV3)?

Back 43

1. The duodenum joins the jejunum
2. Attachment of the ligament of Treitz at the junction with jejunum

Front 44

What is the significance of duodenal recesses?

Back 44

They can trap intestines causing internal hernias.

Front 45

What is the ligament of Treitz also known as?

Back 45

The suspensory muscle of the duodenum

Front 46

In clinics, what is used to distinguish upper from lower GI tract?

Back 46

The ligament of Treitz

Front 47

What are the functions of the ligament of treitz?

Back 47

1. To stabilize the duodenojejunal flexure
2. Regulate the passage of food.

Front 48

The ligament of treitz is a fibromuscular band that connects______ to the __________?

Back 48

1. duodenojejunal flexure
2. right crus of the diaphragm.

Front 49

What are the internal features of the duodenum? (there are 4)

Back 49

1. Smooth lining of the duodenal cap (ampulla)
2. Plicae circulares (circular folds or valves of kerkring)
3. Major and minor duodenal papillae
4. Longitudinal fold

Front 50

What are the two major characteristics of the major duodenal papilla?

Back 50

1. Demarcates the junction between the embryonic foregut and midgut
2. Contains an opening of hepatopancreatic ampulla

Front 51

What two structures form the hepatopancreatic ampulla?

Back 51

1. The pancreatic duct
2. The common bile duct

Front 52

Describe the development of the stomach (growth and rotation)

Back 52

A. Growth
i. Differential growth in its dorsal wall results in: the greater curvature, fundus, and cardiac incisure.
ii. Slower expansion in ventral wall results in the lesser curvature.
B. Rotation of the stomach around 2 axes during 7th-8th week:
i. 90 degrees clockwise rotation along longitudinal axis shifts the greater curve to the left
ii. rotation around dorsoventral axis pushes the greater curvature inferiorly.

Front 53

Describe the development of the duodenum

Back 53

1. The duodenum develops from:
*caudal part of the foregut *cranial part of the midgut
* associated splanchnic mesenchyme
2. Parts grow rapidle formaing a C-shaped loop that projects ventrally
3. As the stomach rotates, the duodenal loop rotates to the right. The rotation along with the rapid growth of the head of the pancreas pushes the duodenum towards the right side of the abdomen against the dorsal body wall.
The dorsal mesoduodenum degenerates making the duodenum secondarily retroperitoneal, except at the duodenal cap, where it maintains its mesentary.