The digestive system breaks down food into smaller molecules that can be absorbed and used by the body. It begins with ingestion in the mouth and moves through the esophagus, stomach, and small and large intestines. The digestive tract secretes enzymes and acids to break down lipids, proteins, and carbohydrates at each stage. Nutrients are then absorbed through the intestinal walls and transported to cells while waste is eliminated through the large intestine and anus. Common digestive disorders include irritable bowel syndrome, ulcers, and colon cancer. New treatments aim to aid digestion through devices like gastric bands or bypass surgery.

1. The Digestive System
A Report By: Alinor A. Mamongcara

2. The Digestive System Song

3. Gastroenterology
• Study of the digestive system and its
disorders

4. Digestion
The chemical breakdown of complex
biological molecules into their component
parts.
• Lipids to fatty acids
• Proteins to individual amino acids
• Carbohydrates into simple sugars

5. Digestion
• Mechanical
–Changes the physical form of food
•Chew
•Tear
•Grind
•Mash
•Mix

6. Functions of the Digestive
System
• Produces various chemicals to break
down the food.
• Filters out harmful substances.
• Gets rid of solid wastes.

7. Phases of Digestion
• Ingestion
• Movement
• Digestion
• Absorption
• Further digestion

8. The Digestive Tract
• A long muscular
tube with many
sections and
areas.
• Begins with the
mouth and ends
with the anus.

9. The Digestive Tract
• Parts of the
Digestive Tract
–Mouth
–Pharynx
–Esophagus
–Stomach
–Small Intestine
–Large Intestine

10. Mouth
• Functions:
– Food enters in the
mouth or oral cavity
– Tasting
– Mechanical
breakdown of food
– Secretion of salivary
glands (salivary
amylase)

11. Esophagus
• A straight muscular tube that
is about 10 inches (25 cm)
long which connects the
mouth with the stomach
• Food takes about 4 to 8
seconds as it passes through
to the stomach.
• Its walls contain smooth
muscles that contracts in
wavy motion (Peristalsis).
• Peristalsis propels food and
liquid slowly down the
esophagus into the stomach.

12. Stomach
• J-shaped muscular sac
• Has inner folds (rugae) that
increases the surface area of
the stomach.
• Churns and grinds together
the bolus into smaller pieces.
• Food is mixed with gastric
juices (hydrochloric acid and
enzymes) secreted by the
stomach walls.
• HCL helps break down food
and kills bacteria that came
along with the food.

13. Small Intestines
Site of greatest amount of digestion
and absorption, 90% of the process
• Takes about 4 – 8 hrs to complete
its journey.
• Mucosa (inner wall) – secretes
several enzymes that acts on the
food.
• Digested nutrients are absorbed
through intestinal walls.
• Absorbed materials cross the
mucosa into the blood then other
parts of the body for storage or
further chemical change.

14. Large Intestine
• a.k.a. Colon
• larger diameter, but shorter (5 ft)
• Water is absorbed from the
undigested food making the waste
harder until it becomes solid.
• Waste stays for 10 – 12 hours.
• Waste is pushed into the expanded
portion (rectum) of the large
intestine.
• Solid waste stays in the rectum
until it is excreted through the anus
as feces.
• Appendix hangs on the right side
of the large intestine.

15. Common Diseases of the
Digestive System
• Irritable bowel syndrome
• Lactose intolerance
• Peptic ulcer
• Colon Cancer
• Loose Bowel Syndrome (Diarrhea)

16. Latest Trends
• Pivot (Pacemaker for the Digestive
System)
– The chips can slow the emptying of the
stomach, triggering feeling of fullness in
obese patients.
• Gastric Bypass
– divides the stomach into a small upper pouch
and a much larger lower "remnant" pouch and
then re-arranges the small intestine to
connect to both.

17. Latest Trends
• Adjustable Gastric Band
– an inflatable silicone device placed around the
top portion of the stomach to treat obesity,
intended to slow consumption of food and
thus the amount of food consumed.

18. Trivia
• The esophagus is approximately 25cm long. Muscles
contract in waves to move the food down the
esophagus. This means that food would get to a
person's stomach, even if they were standing on their
head.
• The digestive tract is similar to a long tube which is
approximately 30 feet (Equal to 5, 6 footers) long in
total running through the middle of the body.

19. Reporter’s Profile
• Alinor A. Mamongcara
– Studies at Adamson University
taking up BS Accountancy
– 09-23-87
– Gave up working for HSBC in a span
of 5 years to pursue his studies
– Gaming and Gadget Enthusiast
– Favorite Qoute:
“The only thing necessary for evil to
triumph, is for good men to do nothing”
–Edmund Burke

20. A Short Video About the
Digestive System