[问答题,简答题] 什么是U值？

胫神经支配() ["A．胫骨前肌 ","B．胫骨后肌 ","C．腓骨长肌 ","D．腓骨短肌 ","E．小腿三头肌"] 循证医学 半衰期 视觉性语言中枢()运动性语言中枢() ["A．优势半球额下回后部 ","B．优势半球角回 ","C．优势半球额上回后部 ","D．优势半球额中回后部 ","E．优势半球颞上回后部"] 股神经支配() ["A．股二头肌 ","B．股四头肌 ","C．缝匠肌 ","D．半腱肌 ","E．半膜肌"] 什么是U值？