1. Unit 5 Notes: Digestion Basics, The Mouth, and The Esophagus

2. (1) Digestion Basics Organs: Functions: Oral Cavity Esophagus Stomach
Small Intestine
Large Intestine
Functions:
Metabolize biomolecules.
Absorb useful nutrients into blood stream.
Excrete waste, irritating or non-useful compounds.

4. (2) Dig. In The Mouth Both Mechanical & Chemical Digestion Mechanical:
Teeth chewing + grinding breaks down food into smaller units
Chemical:
Enzymes in saliva breaks down parts of food

5. (3) Saliva & Digestion Saliva = Spit
Lubricates food for esophageal transfer
Contains an enzyme called AMYLASE…
Breaks down starch  maltose

7. (4) Saliva Reflexes Parasympathetic release of saliva Causes:
Pressure in mouth
Smell / Sight of food
Thinking about food
Emotional connection to food

9. (5) Bolus Bolus = chewed up food, mixed with saliva.
Bolus travels from mouth  esophagus.

12. (6) Deglutition Buccal Phase (Voluntary):
(A.K.A. – Swallowing)
Buccal Phase (Voluntary):
Tongue moves bolus into pharynx
Pharyngeal-Esophageal Phase (Involuntary):
Epiglottis closes over larynx
Bolus moves into esophagus

14. (7) In The Esophagus Bolus moves from esophagus  stomach
Food moves through esophagus using PERISTALSIS:
Peristalsis = Involuntary contraction of muscle
Wave-like contractions push food down
Like a tube of toothpaste!