All descriptions of the human body are based on the assumption that the person is in the anatomical position. A person in the anatomical position is standing erect with the head， eyes， and toes directed forward， the heels and toes together， and the upper limbs hanging by the sides with the palms facing anteriorly. You must always visualize the anatomical position when describing patients or cadavers lying on their backs （supine position）， sides， or fronts （prone position）。 Otherwise， confusion as to the meaning of your description will exist and serious consequences could result.

　　人体结构的描述是以人体解剖方位的设想为基础的。人体解剖方位的基本设想是：人体直立，头、两眼和脚趾指向前方，脚趾和脚跟靠拢，上肢垂于两侧，手掌向前。在描述背朝下（仰卧）、身体一侧朝下、或正面朝下（俯卧）而卧的病人或尸体时，都应始终按解剖方位进行，否则，人们就会对你的描述感到迷惑不解，并导致严重后果。