SM_142b: Clinical Features of Malabsorption

Question 1

Majority of fluid and nutrients are absorbed in the ____

Answer 1

Majority of fluid and nutrients are absorbed in the small bowel

• Four stages: ingest, process, lumen -> mucosa, mucosa -> circulation

Question 2

Malabsorption is ____

Answer 2

Malabsorption is imapired absorption of ≥ 1 of protein, carbohydrate, fat, or micronutrients

• Leads to malnutrition

Question 3

Protein absorption ____, ____, ____, and ____

Answer 3

Protein absorption

• Pancreatic enzymes
• Pepsinogen -> pepsin
• Brush border enzymes
• Active / passive absorption

Question 4

Trypsinogen -> trypsin via ____

Answer 4

Trypsinogen -> trypsin via enterokinase

Question 5

Protein malabsorption is caused by ____ due to ____ and ____

Answer 5

Protein malabsorption is caused by mucosal injury and lymphatic obstruction

• Signs / symptoms related to underlying cause (portal hypertension), diarrhea sometimes, edema / anasarca, ascites, reduced muscle mass / function

Question 6

Carbohydrate absorption involves ____, ____, and ____

Answer 6

Carbohydrate absorption involves salivary amylase, brush border enzymes, and active / passive absorption

Question 7

Carbohydrate absorption involves ____ and ____ in the brush border and ____ in the basolateral membrane

Answer 7

Carbohydrate absorption involves SGLT1 and GLUT5 in the brush border and GLUT2 in the basolateral membrane

Question 8

Carbohydrate malabsorption often involves ____ or ____

Answer 8

Carbohydrate malabsorption often involves lactose (lactase deficiency) and fructose (mechanism unclear)

• Presents with gas / bloating, abdominal discomfort / distention, and diarrhea after eating carbohydrate

Question 9

Fat absorption involves ____ and ____

Answer 9

Fat absorption involves pancreatic enzymes and absorption in ileum

Question 10

Fat malabsorption results from ____, ____, and ____

Answer 10

Fat malabsorption results from impaired mixing (bile salt deficiency), impaired breakdown (pancreatic insufficiency), and impaired absorption (anatomic)

• Presents with steatorrhea (greasy, foul smelling stools, usually difficult to flush), weight loss, and nutrient deficiencies

Question 11

Vitamin / mineral absorption is ____ based

Answer 11

Vitamin / mineral absorption is anatomically based

• Duodenum: heavy metals
• Jejunum: heavy metals, some non-fat soluble vitamins
• Ileum: fat soluble vitamins, vitamin B12

Question 12

____ are absorbed in the duodenum

Answer 12

Heavy metals are absorbed in the duodenum

Question 13

____ and ____ are absorbed in the jejunum

Answer 13

Heavy metals and some non-fat soluble vitamins are absorbed in the jejunum

Question 14

____ and ____ are absorbed in the ileum

Answer 14

Fat soluble vitamins and vitamin B12 are absorbed in the ileum

Question 15

Celiac disease is a ____ that is typically ____

Answer 15

Celiac disease is a small bowel enteropathy that is typically proximal (iron deficiency)

Question 16

Fat malabsorption occurs when < 10% of ____ is available

Answer 16

Fat malabsorption occurs when < 10% of pancreatic exocrine function is available