QuestionSBA
QuestionChoice
This is not the correct answer. This is where the majority of the absorption of iron takes place. The absorption of vitamin B12 takes place mainly in the terminal ileum.
10027422
b
Duodenum
QuestionChoice
This is not the correct answer. The stomach is where intrinsic factor (IF) is secreted by gastric parietal cells. B12 then binds to IF to be absorbed in the terminal ileum.
10027423
c
Stomach
QuestionChoice
This is not the correct answer. This is where the majority of the absorption of vitamin B3 (niacin) takes place. The absorption of vitamin B12 takes place mainly in the terminal ileum.
10027425
e
Upper ileum
QuestionChoice
This is not the correct answer. This is where amino acids, folic acid, iron, water, sugars (glucose, fructose, galactose, maltose), and various other substances are absorbed. The absorption of vitamin B12 takes place mainly in the terminal ileum.
10027424
d
Duodenom and upper jejunum
QuestionChoice
This is the correct answer. Vitamin B12 binds to an intrinsic factor (secreted by gastric parietal cells in the stomach), which then binds to specific receptors in the terminal ileum for absorption called cubulin. The B12 is then absorbed and binds to transcobalamin.
10027421
a
Terminal ileum
Concept
Chapter
2693
5977
Digestion and absorption in the small intestine
Topic
149
Gastro-intestinal physiology
17882
Where is vitamin B12 primarily absorbed?
a