原发性弯曲
Curvaturae primariae
定义
胸曲和骶曲（盆曲）被称为原发性弯曲，因为它们是胎儿期唯一存在的弯曲。
參考資料
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
