4/25: Overview, Saliva, Mastication and Swallowing II Flashcards
What are the three functions of the esophagus?
- Transport of solids and liquids from pharynx to stomach
- Prevents air intake - UES
- Prevents reflux (stomach to esophagus) - LES
What is peristalsis?
wave of contraction that moves bolus through esophagus
What are the two types of peristalsis?
- Primary Peristalsis
- Secondary peristalsis
What is primary peristalsis?
continuation of peristaltic wave initiated during pharyngeal phase of swallowing (8-10 sec)
What is secondary peristalsis activated by?
activated by esophageal distension from retained food in esophagus
What is the upper 1/3 of the esophagus controlled by?
Somatic nerves regulate striated muscle directly
What are the remaining 2/3 of the esophagus controlled by?
Autonomic nerves regulate smooth muscle via enteric nervous system or directly
What is primary peristalsis defined by?
Wave of relaxation in front of bolus
Wave of contraction behind bolus
What is secondary peristalsis function?
- Clearing a bolus that was not wholly expelled by primary wave
- Removing any gastric contents that reflux back into the lower esophagus
When do upper and lower esophageal sphincters remain closed?
Between swallows
What properties do esophageal sphincters have?
Tonic contractile properties
What sphincter relaxes during swallow?
Upper esophageal sphincter
What sphincter relaxes as peristaltic wave approaches?
Lower esophageal sphincter
What is GERD?
Reflux of gastric contents into esophagus
- common and potentially disabling
What is GERD treated by?
Inhibiting gastric acid secretion
