Anatomy and Physiology of the Mouth and Pharynx

What are the boundaries of the mouth?

The lips (anterior), cheeks (lateral), palate (superior), and tongue (inferior)

What are the two regions of the mouth?

Oral vestibule and oral cavity proper

What is the oral vestibule?

The space between the lips and teeth

What is the oral cavity proper?

The space internal to the teeth

What lines the mouth histologically?

Non-keratinized stratified squamous epithelium with areolar CT lamina propria (some areas partially keratinized)

What is the tongue mainly composed of internally?

Skeletal muscle

What are the three functions of the tongue?

Manipulates food during chewing, initiates swallowing, and assists in speech

What is the function of teeth?

Tear and grind food during mastication

What are the three regions of a tooth?

Root, neck, and crown

What is the root of the tooth?

Part embedded in socket (alveolus), non-visible portion

What is the neck of the tooth?

Thin region between root and crown, at level of gums

What is the crown of the tooth?

Exposed part used for chewing

What is enamel?

Superficial layer covering the crown, made of hydroxyapatite crystals, hardest substance in body, non-living

Why can enamel not be repaired?

It is not supported by living cells

What is dentin?

Thick layer under enamel, found in root, neck, and crown, bone-like but without living cells

What are dentinal tubules?

Small tubes found in dentin

What is the pulp cavity?

Hollow center in the crown and neck; contains blood vessels, nerves, and dentin-maintaining cells

What is the root canal?

Canal in root with blood vessels and nerves

What is the apical foramen?

Hole at tip of root where vessels and nerves enter/exit the tooth

What is cement in teeth?

Calcified CT covering the root, attaching to periodontal ligament

What is the periodontal ligament?

Dense CT attaching tooth (via cement) to socket in maxilla or mandible

What are the four types of teeth and their functions?

Incisors (cutting), Canines (tearing), Premolars (crushing), Molars (grinding)

What is saliva composed of?

Water, ions, mucus, buffers, and enzymes

What is a bolus?

A moist ball of chewed food coated in mucus

What do minor salivary glands secrete?

Lingual lipase

Where are the parotid glands located?

Anterior to ear, superficial to masseter

What type of acini do parotid glands have?

Serous acini

What enzyme do parotid glands secrete?

Salivary amylase

Where does the parotid duct empty?

Lateral to second molar in the roof of the mouth

Where are the sublingual glands located?

Deep to the tongue

What type of acini do sublingual glands have?

Mucus acini

Where do sublingual ducts empty?

Under the tongue (10–12 ducts)

Where are the submandibular glands located?

Medial surface of the mandible near the angle

What kind of secretions do submandibular glands produce?

Mixed: mucus and serous (including salivary amylase)

Where do submandibular ducts empty?

Under the tongue, anterior to the first sublingual duct

What muscle type is in the pharynx?

Involuntary skeletal muscle

What is the function of the pharynx in digestion?

Produces peristaltic contractions to move bolus toward the esophagus

What kind of digestion occurs in the mouth?

Mechanical (chewing) and limited chemical; no absorption

What does salivary amylase do?

Breaks down starch/glycogen into maltose

How effective is salivary amylase?

Digests ~10% of polysaccharides before being denatured in the stomach

What does lingual lipase do?

Breaks down triglycerides into fatty acids and monoglycerides

How effective is lingual lipase?

Digests ~5% of triglycerides before being denatured; limited by lipid droplet size

Does protein digestion occur in the mouth/pharynx/esophagus?

No