Lecture 3: Muscles of the Face, Jaw, and Tongue

Question 1

What are the names, attachments, functions, and innervations for the face, jaw, and tongue muscles?

Answer 1

• Orbicularis oris
• Buccinator
• Risorius
• Levator labii superioris
• Levator labii superioris alaeque nasi
• Zygomaticus (major and minor)
• Depressor labii inferioris
• Mentalis
• Depressor anguli oris
• Levator anguli oris
• Platysma

Question 2

What are the names and innervations of the salivary glands? How much saliva and what kind of saliva does each produce?

Answer 2

• Parotid Gland (CN IX: glosspharyngeal)
  
  • ~25% of oral secretions
  • Output duct in cheek next to 1st molar
• Submandibular Gland (CN VII: facial)
  
  • ~70% of oral secretions
  • Output under tongue
• Sublingual Gland (CN VII: facial)
  
  • ~5% of oral secretions
  • Output ducts under tongue, along the lower teeth

Question 3

What are the functions of saliva and the disorders of salivation?

Answer 3

• Two types of saliva
  
  • Viscid, mucous fluid (thicker)
  • Serous fluid (thinner)
• Parotid gland produces serous fluid
• Submandibular gland produces both (mostly serous)
• Sublingual gland produces both (mostly mucous)
• Critical to the health of the oral cavity
• Saliva has antibacterial, antiviral, antifungal, and antacid properties that helps to prevent tooth decay and infections of the oral mucosa (Zalewska, Zwierz, Zolkowski, & Gindzienski, 2000)
• Also responsible for regulating frequency of swallowing
• Amount of saliva accounts for majority of individual variation in swallowing frequency (Rudney, Ji, & Larson, 1995)
• Xerostomia: dry mouth; can result from disease, medications, radiation treatment, neural damage, hormonal fluctuations, and normal aging
• Water brash: too many secretions in the oral cavity due to refluxing saliva and gastric fluids

Question 4

What does it mean when a tongue is a “muscular hydrostatic”?

Answer 4

• Maintains a constant volume as the muscles contract
• Provides own skeletal support
• Muscular contraction
• Incompressibility of internal fluids

Question 5

Which muscles are intrinsic?

Answer 5

Question 6

Which muscles are extrinsic?

Answer 6

Question 7

What are the divisions of the tongue?

Answer 7

Tip

• Apex of tongue, most anterior part

Blade

• Lies right in back of the alveolar ridge

Dorsum (Body)

• Main mass of tongue, in front of the root

Root

• Most dorsal part of tongue