Esophagus/Stomach

Question 1

Which of the following statements is incorrect in regards of esophageal vascular supply ?
A. cervical esophagus: cr. & cd. thyroid artery, external jugular vein.
B. cranial 2/3rds of the thoracic esophagus: bronchoesophageal a, azygos vein
C. caudal 1/3 thoracic esophagus: esophageal branches of aorta or dorsal intercostal a. and azygous vein
D. Terminal portion: esophageal br. of right gastric artery, portal venous system

Answer 1

D Terminal portion = left gastric artery and left gastric vein –> portal venous system

Question 2

Factors contributing (5) to healing of the esophagus:

Answer 2

1 lack of serosa,
2 segmental blood supply, 
3 lack of omentum, 
4 constant motion (swallowing and respiration), 
5 tension at the surgical site

Question 3

T/F: Simultaneous ligation of blood vessels to the cervical and thoracic esophagus, results in esophageal necrosis at the thoracic inlet.

Answer 3

True: BUT
Most cases of ischemic necrosis at the esophageal incision associated w/ damage to the intramural vascular supply of esophagus rather than the segmental vessels.

Question 4

Which is true?
A 57% of dogs undergoing ortho procedures have a gastroesophageal reflux event
B 35% of these events are recognized.
C Small amounts of food 3 hours before surgery can increase the acidity.
D Ranitidine is a proton-pump inhibitor

Answer 4

A true
B (14%)
C (decrease)
D H 2 blocker

Question 5

What are 4 branches of the vagus that supply the esophagus

Answer 5

paired pharyngoesophageal
recurrent laryngeal
pararecurrent laryngeal
dorsal and ventral vagal trunks

Question 6

What occurs in the 3 steps of oropharyngeal phase of swallowing?

Answer 6

oral: prehension, bolus formed, delivered to pharynx
Pharyngeal: prevent nasal reflux(palatal and pharyngeal m contraction) and laryngotracheal aspiration (caudal epiglottic reflection+vocal fold adduction)
cricopharyngeal: bolus delivered to cranial cervical esophagus (relax thyropharyngeus and cricopharyngeus)

Question 7

What are 2 forms of movement of food in the esophagus in esophageal phase of swallowing?

Answer 7

primary peristaltic wave (large enough bolus)

secondary peristaltic wave (from distension esoph)

Question 8

Where does aorta cross?

Answer 8

midthoracic esophagus

Question 9

Name layers of esophagus

Answer 9

adventitia
muscularis
submucosa
mucosa

Question 10

What are contributors to the lower esophageal high pressure zone? (4)

Answer 10

1 circumferential striated m. thickening (dogs),
2 diaphragmatic crural muscles
3 angle of esoph+stomach
4 folds gastroesophgeal mucosa

Question 11

Transit time of liquid/kibble in sternal recumbency?

Answer 11

2.58/4.44 cm/s

slower in lateral 7.23 /8.92 cm/s

Question 12

name layers of the stomach and sublayers

Answer 12

serosa
muscularis: longitudinal, inner, oblique
submucosa
mucosa

Question 13

What structures does the cardiac notch separate? the incisura angularis/ angular notch?

Answer 13

Cardia and fundus

antrum and the body at lesser curvature

Question 14

where does the hepatogastric ligament come from?

Answer 14

portion of the lesser omentum

Question 15

Where does the gastrosplenic ligament come from? What does it contain?

Answer 15

splenic portion of the greater omentum

gastroepiploic vessels

Question 16

What do the following gastric glands produce?
cardiac
pyloric
parietal
chief
endocrine

Answer 16

cardiac: serous
pyloric: mucus
parietal/oxyntic: pump H+ ions into lumen; intrinsic factor
chief: pepsinogen
endocrine: gastrin; histamine; serotonin

Question 17

What does intrinsic factor do?

Answer 17

binds B12 to permit absorption in distal small intestine

Question 18

Why is contractile retropulsion important in the stomach

Answer 18

reduces digestible food particles to 0.1-0.63mm

Question 19

How is wound healing/collagen production different in GI tract?

Answer 19

fibroblasts AND smooth m. cells contribute to collagen production