脊髓半切损害综合征最常见于() ["A．髓外硬脊膜内肿瘤","B．脊柱结核","C．硬脊膜外肿瘤","D．髓内肿瘤","E．脊髓粘连性蛛网膜炎"]
有关胸核的描述正确的是（） ["A．为排尿排便中枢","B．仅见于颈8至腰5节段","C．仅见于脊髓胸段","D．发出脊髓丘脑束","E．发出至小脑的纤维"]
固定脊髓的结构是() ["A．蛛网膜","B．软脊膜","C．马尾","D．脊髓圆锥","E．齿状韧带"]
何谓肿瘤的演进与异质化?
传导触觉的纤维束() ["A．包括脊髓丘脑侧束","B．起始于胶状质细胞","C．均起白灰质后柱","D．包括薄束和楔束","E．全部为交叉纤维"]
简述肿瘤异型性与肿瘤分化程度及良恶性的关系。
