Unit 2: Digestion in The Mouth & Esophagus

(1) Digestive Organs Oral Cavity Esophagus Stomach Small Intestine Large Intestine

(2) What happens in the mouth? Food is digested in the mouth both mechanically and chemically. Mechanically  Teeth chew and physically break down food into smaller units.| Chemically  Enzymes in your saliva help to break down biomolecules in food.

(3) Chemical Digestion in the Mouth Saliva lubricates food for esophageal transfer. Saliva contains an enzyme called Amylase. Amylase breaks down polysaccharides like starch into disaccharides.

(4) Mouth to Esophagus Once food is chewed up and mixed with saliva, it is ready to travel down the esophagus. Chewed up food mixed with saliva is called “Bolus”. Bolus should be completely soft and moist.

(5) Swallowing Deglutition is the proper term for swallowing. There are 2 Phases of Deglutition: The Buccal Phase  Voluntary The tongue moves the bolus into the pharynx and back of the throat. The Pharyngeal-Esophageal Phase  Involuntary The epiglottis closes over the larynx. Bolus is pushed down into the esophagus

(6) Traveling thru the Esophagus The esophagus is the highway between the mouth and stomach. Food is pushed through the esophagus using Peristalsis. Peristalsis  Involuntary, wave-like contraction of muscle used to push softer / more liquid-like substances through an organ.