Anatomy & Physiology of Swallowing

Cranial Nerves Important in Swallowing

• Overview
  • CN V -- Trigeminal
    • contains both sensory and motor fibers that innervate the face
    • important in chewing
    • located at the level of the pons
  • CN VII -- Facial 
    • contains both sensory and motor fibers
    • important for sensation of oropharynx & taste to anterior 2/3 of tongue
  • CN IX -- Glossopharyngeal
    • contains both sensory and motor fibers
    • important for taste to posterior tongue, sensory and motor functions of the pharynx
  • CN X -- Vagus
    • contains both sensory and motor fibers
    • important for taste to oropharynx, and sensation and motor function to larynx and laryngopharynx.
    • important for airway protection
  • CN XII -- Hypoglossal
    • contains motor fibers that primarily innervate the tongue
• Other links about Cranial Nerves
  • Dr. Norman's CN chart

Esophageal Anatomy

• The Longitudinal Muscle in Esophageal Disease

Head and Neck Anatomy

• Instant Anatomy
• Dr. Norman's Webpage

Infant/Children Anatomy

• Issues in Anatomy & Physiology by Dr. Evans-Morris
• Infant Feeding

Laryngeal Anatomy

• Dr. Norman's Larynx Anatomy

Neuroanatomy

• Basic Neural Processes
• Whole Brain Atlas

Oral Anatomy

• Dr. Norman's Oral Anatomy

Pharyngeal Anatomy

• Dr. Norman's Pharynx Anatomy

Taste & Smell

• A tutorial by Tim Jacob

Skull Anatomy

• Dr. Norman's Skull Anatomy

Swallow Physiology

• Adult swallow physiology overview
  • Oral Phase
    • Oral Preparatory
    1. Goal: reduce food to a bolus and position it for transport
    2. Initial transport (the bolus lacement) - tongue positions the food to ready it for reduction
    3. Reduction phase - bolus is chewed & mixed with saliva
    4. Bolus placement - bolus is positioned for transport
    • Oral Transport
    1. The prepared bolus is transported from anterior to posterior oral cavity for passage to the pharynx.
  • Pharyngeal Phase
    1. Complete closure of velopharyngeal opening.
    2. Hyoid & Larynx begin their superior ascent
    3. Epiglottis begins to downfold
    4. Tongue base to posterior pharyngeal wall contact
    5. Top to bottom contractions of pharyngeal constrictor muscles
    6. Continued superior movement of hyoid & larynx
    7. Laryngeal closure starts from bottom up
    8. Continued down-folding of epiglottis to inverted position
    9. Anterior movement of hyoid
    10. Relaxation of cricopharygeus muscle & opening of upper esophageal sphincter region
  • Esophagel Phase
    1. Peristalsis carries the bolus through esophagus to the stomach.
    2. The lower espohageal sphincter opens.

Visible Human Project