Blood supply Ophthalmic artery- anterior posterior ethmoidal arteries (Internal carotid system) Internal maxillary 43 artery- sphenopalatine artery infraorbital artery、 greater palatine artery Little's area--nasopalatine, anterior ethmoidal, posterior (External carotid system) ethmoidal, superior labial greater palatine arteriesBlood supply Ophthalmic artery—— anterior & posterior ethmoidal arteries (Internal carotid system) Internal maxillary artery—— sphenopalatine artery、 infraorbital artery、 greater palatine artery (External carotid system) Little’s area——nasopalatine, anterior ethmoidal, posterior ethmoidal, superior labial & greater palatine arteries