pí fū / shàng / de / wēi xuè guǎn / fēi cháng / xì xiǎo / ròu yǎn / jī hū / kàn bù jiàn皮肤上的微血管非常细小，肉眼几乎看不见。The capillaries on the skin are very tiny and almost invisible to the naked eye.