under the skin

基本解释

It's a spider's web of muscles and tendons under the skin, many of them unique to the human hand.
手掌皮肤下的肌肉和肌腱密如蜘网，其中许多肌肉和肌腱，仅仅是人手所特有的。
dict.cn
Advanced gout. Untreated gout may cause deposit of urate crystals to form under the skin in nodules called tophi(TOE-fi).
未经治疗的痛风会使皮肤下沉积尿酸结石从而形成结节，成为结节瘤。
The fertilized female worm(s) (which measures from 60–100 cm long) migrates under the skin tissues until it reaches the lower limbs, forming a blister or swelling from which it eventually emerges.
受精后的雌虫（有60-100厘米长）在皮肤组织以下游走，一直游到下肢，形成一个水疱或者造成肿胀，虫子最终会钻出来。

They are connected under the skin to another wire that leads to a small battery placed in the chest.
If you get bacteria under your skin, if you get a cut and somehow that cut gets - bacteria gets inside there, the bacteria can reproduce on their own.
如果你皮肤里有细菌,而你又割伤了自己,并让细菌进入了伤口,细菌自身就可以繁殖
耶鲁公开课 - 生物医学工程探索课程节选
The electricity comes from a small power supply placed under the skin in the chest.

These fats can fill macrophages to form small to large nodules under the skin called xanthomas.
FORBES: Europe Takes The Lead Toward Approval Of First Gene Therapy Drug