试述缓冲碱(BB)的概念及其变化的临床意义。
具有止血不留瘀、化瘀不伤正之特点的药物为() ["白及","三七","茜草","藕节","蒲黄"]
既能凉血止血,又能散瘀消痈,善治尿血的药物是() ["槐花","小蓟","侧柏叶","大蓟","苎麻根"]
患者,女,55岁,体弱,少气懒言,乏力自汗,面色苍白,宜选用的药物是() ["味酸","味苦","味甘","味辛","味咸"]
患者,女,30岁,头痛,恶寒,项背僵硬疼痛,首选药物应() ["归肺经","归心经","归膀胱经","归脾经","归肝经"]
试述碳酸氢盐的概念及其变化的临床意义。