1.
inside the body, within the body
The interior of a living body. Used as a noun that often modifies other nouns with の to describe things existing or occurring within the body.
体内の水分が不足している。
There is insufficient water in the body.
薬は体内で吸収される。
The medicine is absorbed inside the body.
体内に蓄積された毒素を排出することが大切だ。
It is important to expel the toxins that have accumulated in the body.
Composed of 体 (body) + 内 (inside). Functions primarily as a noun modifier with の: 体内の～ (something inside the body).
USAGE:
Common in medical, health, and scientific contexts. Less common in casual conversation.
COMMON COLLOCATIONS:
- 体内時計: biological clock
- 体内に取り込む: to take into the body
- 体内の水分: moisture in the body
- 体内に蓄積する: to accumulate in the body
- 体内環境: internal body environment
CONTRAST:
- 体内: inside the body
- 体外: outside the body (e.g., 体外受精 = in vitro fertilization)