1. Daniel Condo 11th Grade Health
The Digestive System
Daniel Condo
11th Grade Health

2. Functions of the Digestive System
Ingestion
Digestion
Movement/Propulsion
Absorption
Elimination

3. Order of Digestion Mouth Pharynx Esophagus Stomach Small Intestine
Large Intenstine
Rectum and Anus

4. Mouth Functions: Ingestion, Digestion, and Movement
-Ingestion: - Taking in food and chewing
-Digestion: - Mechanical breakdown= Teeth (chewing)
- Chemical breakdown= Saliva (Enzymes)
-Movement: -Tongue pushes food to back of mouth
- Swallowing Reflex starts in mouth, moving food into the Pharynx

5. How many teeth are in your mouth?
Extra Credit Question
How many teeth are in your mouth?
Answer = 32

6. Pharynx Commonly known as the Throat Functions: Movement
-Movement: - Swallowing Reflex
- Tongue blocks food from going back into mouth
- Nasal passage is blocked off
- Larynx or Windpipe is blocked off
- Constrictor muscles move food to the esophagus

7. Esophagus Function: Movement
-Movement: - Upper Sphincter* opens allowing food in from the Pharynx, then closes
- Peristalsis** moves the food down the Esophagus
- Lower Sphincter opens to pass food into the Stomach, then closes
*Sphincter = muscular opening
**Peristalsis = Involuntary , wave-like muscular movement

8. Stomach Functions: Digestion, Absorption, Movement
-Digestion: - Mechanical breakdown occurs when involuntary muscles of stomach churn food with Gastric Juices (stomach acid)
- Chemical breakdown occurs when gastric juices (including enzymes) separate food into smaller molecules
- Lower Sphincter of Esophagus closes when mixing to keep out gastric juices

9. Stomach cont.
-Absorption: - Now broken down into smaller molecules some nutrients can be absorb by the stomach wall
- Stomach wall (Rugae) unfolds allowing more surface area for absorption
-Movement: -Sphincter opens at base of the stomach to allow food (Chyme) into Small Intestine
- Peristalsis of stomach moves it into SI

10. Better Understanding of the Stomach
KEs

11. Small Intestine Functions: Digestion, Absorption, Movement
-Digestion: - Chyme is exposed to more enzymes from
ducts lining the SI
- Majority of digestion is done in the Small Intestine; mainly chemically
- Nutrients are now broken down into easily absorbable compounds

12. Small Intestine cont.
-Absorption: - SI is the longest section of the Digestive System to maximize absorption
- Also takes the longest for food to travel to again maximize absorption
- SI is lined with small finger-like folds called Villi which absorb nutrients while creating more surface area
-Movement: - SI is lined with two layers of muscle that pass chyme into the Large Intestine through peristalsis

13. Large Intestine Functions: Absorption, Movement
-Absorption: - Large Intestine absorbs water and electrolytes from remaining chyme
- LI also forms remaining chyme, which is mainly waste, into feces
- Movement: - LI utilizing peristalsis to some extent
- Main movement is cause by large muscular contractions 2-3 times a day

14. Rectum
Function: Elimination -Elimination: - Main function of the rectum is store feces until an appropriate time for excretion

15. Anus Function: Elimination -Elimination: - Anus has 2 Sphincters
- Internal sphincter opens involuntary and brings on the sensation of having to “go”
- The External sphincter is controlled voluntarily and allows to choose when you “go”

16. What you need to know Functions of Digestive System Order of Digestion
Main job of each organ