Stomach & Esophagus

Question 1

Boundaries of the esophagus

Answer 1

• Superior: Pharygoesophageal junction @ C6 cricopharyngeus muscle (upper esophageal muscle), Cricoid @ C6 (ring of cartilage around trachea)
• Inferior: Stomach @ the esophargogastric junction (T10)

Question 2

Cervical esophagus

Answer 2

• Anterior: Trachea & thyroid
• Posterior: Vertebral bodies
• Lateral: Carotid sheath

Question 3

Thoracic esophagus/superior mediastinum

Answer 3

• Anterior: Trachea (anterior is aortic arch)
• Posterior: Vertebral column
• Lateral: Parietal pleura surrounding lung

Question 4

Level of T4/5

Answer 4

• Bifurcation of right/left bronchus
• Left/Right pulmonary artery
• Arch of the aorta

Question 5

Thoracic esophagus/inferior mediastinum

Answer 5

• Anterior: Left bronchus, left atrium of heart
• Posterior: Vertebral column/descending aorta
• Lateral: Aortic arch & thoracic duct-largest lymphatic duct in body (left) & azygous vein (right)

Question 6

Esophageal constrictions

Answer 6

• Upper: junction of esophagus w/pharynx
• Upper middle: Aorta
• Lower middle: L. main bronchus
• Lower: @ esophageal hiatus

Question 7

Blood Supply of Esophagus (arterial)

Answer 7

• Upper: Inf. Thyroid artery (via subclavian-arch of the aorta)
• Middle: Bronchial artery (via descending aorta)
• Lower: Gastric artery (via descending aorta/celiac trunk)

Question 8

Blood supply of Esophagus (vein)

Answer 8

• Upper: Inf. Thyroid veins
• Middle: Azygous vein
• Lower: L. gastric vein

Question 9

The Watershed of Venous Drainage

Answer 9

• Azygous vein from thorax runs w/esophagus into left gastric vein (on stomach post to liver)
• Portal vein = potro-systemic venous anastomosis

Question 10

What organs are associated w/portal vein?

Answer 10

• Liver (major)
• Stomach
• Spleen
• Large intestine

Question 11

Right Crus of diaphragm

Answer 11

• Passage of esophagus from thorax to abdominal area
• @ the LVL T10
• Superior to the Aortic/thoracic duct of abdominal aorta @ T12
• Vagus nerve runs with esophagus @ right crus

Question 12

Parasympathetic Nervous system

Answer 12

• Right vagus runs along with esophagus into the esophageal plexus
• Plexus @ sphincter of stomach
• Left vagus runs w/esophagus & OVER aortic arch to rejoin @ plexus
• Vagus is CN 10 and innervates stomach/esophagus

Question 13

Musculature of esophagus

Answer 13

• Upper 1/3 = Skeletal/circular
• Middle 1/3 = mixed
• Lower 1/3 = Smooth/longitudinal (peristalsis)

Question 14

Symptoms of Achalasia of Cardia (cardiac sphincter) “Sphincter tightly constricted”

Answer 14

• Barium swallow = “birds beak”
• Food sticks
• Discomfort post. to sternum=heartburn
• Regurgitating unmodified food
• Halitosis
• Weight loss
• Hunger

Question 15

Auerbach’s plexus

Answer 15

• degeneration is linked to achalasia of cardia as cause for constriction
• Hirschsprung’s is a congenital disorder in plexus that effects LI creating blockage of feces due to NO peristalsis.

Question 16

Symptoms of GERD

Answer 16

• Worse after heavy evening meals
• Regurgitates metallic taste
• Mucosal oedema (inflammation=thickening)
• Most common cause is hiatus hernia

Question 17

Layers of Stomach/Esophagus

Answer 17

• Oesophagus = pseudo stratified squamous
• Stomach = columnar (glandular) –>crypts/glands
• Location where esophagus & stomach meet is squamo-columnar junction

Question 18

Oesophago-gastric junction

Answer 18

• Liable due to state of flux
• Cells less stable
• Potential tumors/cancer
• Metaplasia (replacement of one cell type for another)

Question 19

Barrett’s esophagus

Answer 19

• GERD: acid exposure for 5+ years
• Metaplasia of mucosal layer of lower esophagus to squamous gastric columnar type
• Pre malignant condition (death)

Question 20

Esophageal cancer

Answer 20

• Fastest growing cancer in western world
• Due to esophago-gastric junction metaplasia
• Barrett’s and GERD untreated

Question 21

Characteristics of Stomach

Answer 21

• Gastric juices: HCl, pepsin, intrinsic factor
• Mixes food with gastric juices = Chyme
• Protective: bi carb & mucus secretion
• Hormonal: G cells = Gastrin (precursor to HCl from parietal cells)
• Epigastric/LUQ

Question 22

Mesentery

Answer 22

• Complex folding of gut requires maintenance of blood supply, innervation, lymphatic drainage.
• Intraperitoneal: Mesentery double layer of peritoneum BV, nerves, lymphs lie BETWEEN layers
• Retroperitoneal: Covered but NOT wrapped around peritoneum & BV, lymphs, nerves on surface.
• Intraperitoneal = mesentary
• Retroperitoneal = NO mesentary

Question 23

Lesser Omentum/Greater Omentum

Answer 23

• Located superior to stomach (lesser curvature) & inferior to liver
• Portal triad located here (Bile duct, portal vein, hepatic artery)
• Greater Omentum: stretches across inferior border of stomach (Greater curvature) blankets the intestines & connects stomach to TC

Question 24

Stomach anatomy

Answer 24

• superior border: Cardia/fundus
• Middle: Body
• Inside: Rugae
• Inferior border: Antrum/pylorus
• Oblique muscle controls lumen

Question 25

Relations to stomach

Answer 25

- Anterior: Left lobe Liver (URQ) - Ab wall - Posterior: Foramen of Winslow (lesser sac) - Pancreas - Aorta, Left Kidney, Spleen - Inferior - Great omentum - Transverse Colon

Question 26

Stomach Innervation

Answer 26

-Myenteric plexus & Submucosal plexus = Intrinsic innervation - ANS

Question 27

Stomach Innervation (sympathetic/para)

Answer 27

- Symp: Preganglionic T6-T9 -->sympathetic trunk - Parasympathetic: Left (anterior)/right (posterior) vagus - ALL extrinsic innv.

Question 28

GI tract Pain location

Answer 28

- Foregut = Epigastric - Midgut = Umbilical - Hindgut = Pelvic