Alimentary - Stomach & Abomasum

Question 1

4 regions of the stomach

Answer 1

• Esophagus
• Cardia
• Fundus/Body
• Pylorus

Question 2

Region of the stomach containing only stratified squamous epithelium

Answer 2

Esophagus

Question 3

Region of the stomach that secretes mucin only

Answer 3

Cardia

Question 4

Region of the stomach that secretes pepsinogen, HCL & mucin

Answer 4

Fundus / Body

Question 5

Region of the stomach that secretes mucin & gastrin

Answer 5

Pylorus

Question 6

Luminal surface of gastric mucous-secreting cells

Answer 6

Foveolar epithelium

Question 7

Parietal cells secrete:

Answer 7

HCl

Question 8

Chief cells secrete:

Answer 8

Pepsinogen

Question 9

Neuroendocrine cells secrete:

Answer 9

Gastrin

Question 10

What 4 things comprises the gastric mucosal barrier?

Answer 10

1. Mucous gel - protects and lubricates
2. Bicarbonate (HCO3) - acid neutralization
3. Replacement cells
4. Blood Flow

Question 11

What does prostaglandin in the stomach control?

Answer 11

• HCO3 & mucous secretions
• Cell turnover
• Mivrovascular blood flow

Question 12

Superficial mucosal defect limited to mucosa/lamina propria

tend to bleed less

Answer 12

Erosion

Question 13

Deep mucosal defect that extends through epithelium into submucosa

tend to bleed a lot

Answer 13

Ulcer

Question 14

Gastric ulcer sequale

Answer 14

Bleeding
-> anemia
-> internal exsanguination
-> transmural perforation
-> septic peritonitis
-> healing & fibrosis
-> dysmotility or obstruction
-> impaction

Question 15

Acute gastric ulcer appearance

Answer 15

Red-to-brown mucosal depression with active bleeding +/- fibrin layer

Question 16

Chronic gastric ulcer appearance

Answer 16

Raised tan “indurated” crater-like lesion with re-epithelialization +/- active hemorrhage

Question 17

How does a gastric ulcer arise?

Answer 17

Gastric acid secretion overcomes gastric mucosal barrier.
- increased parietal/chief cell secretion

Question 18

Clinical signs of gastric ulcers

Answer 18

Dog/cat: vomiting, inappetance, abdominal pain, anemia, melena
Cattle: anorexia, decreased milk production, melena, positive grunt test
Horses: anorexia, poor performance, bruxism
Swine: anorexia, peracute death

Question 19

Common causes of gastric ulcers

Answer 19

• Vascular Compromise (pharmacologic, supraphysiologic stress, displacements)
• Dietary Disturbance
• ** Trauma/Toxin** (FB, caustic)
• Neoplasm
• Infectious/Inflammatory (GASTRITIS)

Question 20

How do NSAIDs cause vascular compromise & ulcers?

Answer 20

COX (1&2) Inhibition
* Acetylsalicylic acid - PG & TX inhibition
* Carprofen, Deracoxib, Fibrocoxib, Meloxicam - COX2 only
* Acetominophen - TOXIC

Question 21

How do steroids cause vascular compormise & gastric ulcers?

Answer 21

• PLA2 enzyme inhibition, COX inhibition, alpha-inflammatory
• Decrease immune cell activation
• Induce immune cell apoptosis

Question 22

NSAID ulcer sequale

Answer 22

COX enzyme inhibition -> decreased PG synthesis
* increased acid secretion (parietal cells)
* decreased HCO3 & mucus
* decreased microcirculation
* decreased replacement cells

Question 23

True/False

Gastric ulcers can result from gastric displacements and dilations

Answer 23

True

Question 24

Common gastric displacements and dilations

Answer 24

• Bovine abomasal displacements (LDA, RDA)
• Canine GDV syndrome (CV)
• Equine acute gastric dilation (RUPTURE)

Question 25

Dietary disturbances causing gastric ulcers

Answer 25

* **Canine:** dietary indiscretion * **Bovine:** milk -> fiber diet in calves, post-parturient diets * **Swine:** small feed particle size, bleeding ulcers in pars esophagea -> exsanguination

Question 26

Neoplasms associated with gastric ulcers

Answer 26

* Adenocarcinoma (K9) * Squamous Cell Carcinoma (EQ) * Lymphosarcoma (BV BLV > K9, FE) * Mast Cell Tumors (typically outside of stomach)

Question 27

* Gastric neoplasm common in older male dogs * Glandular portion * Infiltrative (not often raised) * Ulcerative (may resemble chronic ulcer) * Desmoplasia -> firm, tan-white * Carcinomatosis * Poor prognosis

Answer 27

Gastric Adenocarcinoma

Question 28

* Gastric neoplasm common in older horses * Squamous portion * Exophytic * Verrucous * Ulcerative * Desmoplasia -> firm, tan-white * Carcinomatosis * Uncommon widespread mets * Poor prognosis

Answer 28

Squamous Cell Carcinoma

Question 29

* Sporadic gastric neoplasm (more common in intestines) in both small & large animals associated with gastric ulcers * Abomasum in cows (BLV in older cows), also epidural, retrobulbar spaces, uterus, heart in cows * Can be associated with FeLV in cats

Answer 29

Lymphosarcoma (Lymphoma)

Question 30

Epi-/Norepinephrine mediated VASCOCONSTRICTION is associated with what mechanism of gastric ulcers in dogs?

Answer 30

Stress

Question 31

COX enzyme inhibition leading to DECREASED prostaglandin is associated with what mechanism of gastric ulcers in dogs?

Answer 31

NSAIDs

Question 32

Local invasion of neoplastic cells with desmoplasia leading to disruption of glands and microvasculature is associated with what mechanism of gastric ulcers in dogs?

Answer 32

Adenocarcinoma

Question 33

* Neoplasm associated with pyloric/anterior duodenal ulcers * Origin in skin, viscera * Result of excess circulating histamine

Answer 33

Mast Cell Tumors

Question 34

* *Clostridium perfringens* culprit causing erosions, ulcers, emphysema, & HEMORRHAGE * Gram+ anaerobe that produces toxins * Seen in ruminants, dogs

Answer 34

Hemorrhagic Abomasitis (calves) Hemorrhagic Gastroenteritis (dogs)

Question 35

* Type of hypersensitivity reaction seen in dogs, cats, horses * Infiltration of eosinophils, lymphocytes, plasma cells * Signs: vomiting +/- diarrhea * Inflammation causing hyperplasia of mucosa, erosions +/-, loss of gastric glands, fibrosis

Answer 35

Immune-Mediated Gastritis (IBD) | Eosinophilic Gastritis/Gastroenteritis