cranial region functions

Incisors

Most anterior, chisel-shaped teeth designed for cutting or slicing food.

Canines

Teeth posterolateral to incisors with pointed tips for puncturing and tearing food.

Premolars

Teeth with prominent cusps between canines and molars used to crush and grind food.

Molars

Thick, posterior teeth with broad crowns adapted for grinding and crushing food.

Premolars vs. Molars (Development)

Premolars replace deciduous teeth, whereas molars erupt as permanent teeth without deciduous predecessors.

Cranial Digestive Structures Location

Primarily located in the cranial region, specifically within the mouth and throat.

Labia (Lips)

Form the anterior oral cavity wall and help close the mouth during chewing.

Oral Cavity

The entrance to the GI tract and initial site of mechanical and chemical digestion.

Vestibule

Space between lips/cheeks and gums where food mixes with saliva and undergoes mechanical digestion.

Gingivae (Gums)

Cover alveolar processes of the upper/lower jaws and surround the necks of the teeth.

Tongue Function

Mixes food during chewing, forms a bolus against the palate, and aids swallowing.

Lingual Frenulum

Thin mucous membrane attaching the inferior tongue surface to the floor of the oral cavity.

Hard Palate

Anterior two-thirds of the roof of the mouth separating oral and nasal cavities.

Soft Palate

Posterior one-third of the roof of the mouth that elevates during swallowing to close the nasopharynx.

Parotid Gland

Located anterior/inferior to the ear; produces about 25-30% of saliva.

Parotid Duct Path

Parotid gland → duct → parallel to zygomatic arch → buccinator → vestibule near second upper molar.

Submandibular Gland

Located inferior to the mandible body; produces about 60-70% of saliva.

Submandibular Duct Path

Submandibular gland → duct → floor of mouth papilla lateral to lingual frenulum.

Esophagus Function

Transports swallowed material toward the stomach using peristalsis.

Digestive Regions: Oral Cavity, Pharynx, Esophagus

Oral cavity receives/digests food; pharynx moves food; esophagus transports to stomach.

Salivary Secretions in Digestion

Moisten food, lubricate, form a bolus, and begin carbohydrate digestion via salivary amylase.

Salivary Gland Paths

Parotid to molar vestibule; submandibular to lateral frenulum; sublingual via tiny ducts to oral cavity.

Mechanical vs. Chemical Digestion

Mechanical physically breaks food; chemical uses enzymes to break down molecules.

Six Main Digestive Functions

Ingestion, motility, secretion, digestion, absorption, and elimination of wastes.

Bolus Pathway After Swallowing

Passes through the pharynx and esophagus via peristalsis toward the stomach.