37th Exam (Jan 2025) Morning Q26 Kaigo Fukushishi
Question (original Japanese)
次のうち、食物の栄養素の大部分を吸収する部位として、正しいものを1つ選びなさい。
- 1胃
- 2小腸
- 3直腸
- 4横行結腸
- 5Ｓ状結腸
Show answer
Correct answer 2
Key pointMost nutrients are absorbed in the small intestine.
Explanation
The small intestine (duodenum, jejunum, and ileum) has circular folds and villi (絨毛) on its inner wall, giving it a large surface area, and it absorbs most nutrients such as carbohydrates, proteins, and fats, so 2 is correct.
- 1: The stomach digests food with gastric juice and makes it into a porridge-like state. It absorbs only some things such as alcohol, so it is wrong.
- 3, 4, and 5: The rectum, transverse colon, and sigmoid colon are parts of the large intestine and mainly absorb water and electrolytes to form stool, so they are wrong.
Explanation in Japanese
小腸（十二指腸・空腸・回腸）は内壁に輪状ひだや絨毛があり表面積が大きく、糖質・たんぱく質・脂質などの栄養素の大部分を吸収するので2が正しい。
- 1：胃は食物を胃液で消化し粥状にする。吸収するのはアルコールなど一部なので誤り。
- 3・4・5：直腸・横行結腸・S状結腸は大腸の一部で、主に水分や電解質を吸収して便を形成するので誤り。