Final answer:
The irregular folds of masticatory mucosa that extend laterally from the incisive papilla are known as palatine rugae. These structures, along with the buccinator muscles and mucous membrane, help in the mechanical breakdown and movement of food in the mouth.
Step-by-step explanation:
The name for the irregular folds of masticatory mucosa that extend laterally from the incisive papilla are called the palatine rugae. These folds are important as they facilitate the movement of food during mastication, enhancing the mouth's ability to break down food mechanically. The mucous membrane of the oral cavity, including the palatine rugae, is made up of non-keratinized, stratified squamous epithelium, which is vital for protecting the underlying tissues from abrasion during eating and speaking. The function of the mucous membrane is notably supported by adjacent muscles like the buccinator muscles in the cheeks which help in manipulating the bolus of food effectively within the oral cavity.