The digestive system of the human body comprises a group of organs working together to convert food into energy for the body. Human Digestive System and Nutrition involve the intake of food by an organism and its utilization for energy. This is a vital process which helps living beings to obtain their energy from various sources. The food which we eat undergoes much processing before the nutrients present in them are utilized to generate energy. This processing is known as digestion. The digestion process involves the alimentary canal along with various accessory organs and organ systems. In humans, the process is quite simple due to our monogastric nature. This means that we have a one-chambered stomach, unlike other animals such as cows, which have four chambers.

2. Introduction
The digestive system is used to breakdown food into
nutrients which then pass into the circulatory system
and are taken to where they are needed in the body.

3.  Phases include:
1. Ingestion
2. Movement
3. Mechanical and Chemical Digestion
4. Absorption
5. Elimination(egestion)
Phases of Digestion

4. Digestion
 Mechanical(physical)
chew, tear, grind, mash and mix
 Chemical
Enzymatic reactions etc.

5. Digestive System Organization
 Structures:
Mouth
Pharynx
Oesophagus
Stomach
Small intestine
Large intestine
Rectum

6. Mouth
 Teeth mechanically break down food
into small pieces.
 Tongue mixes food with
saliva(contains amylase , which helps
breakdown starch).
 Epiglottis: flap-like structure at the
back of the throat that closes over the
trachea preventing food from entering
it.

7. Oesophagus
 Approximately 20cm long.
 Functions:
Secreting mucus and moving food from
the throat to the stomach using muscle
movement called peristalsis.

8. Stomach
 It is J-shaped muscular bag that stores the
food and breaks it down into tiny pieces.
 Mixed food with gastric juices that contains
enzymes to breakdown proteins and lipids.
 Hydrochloric acid in the stomach kills
bacteria.
 Food found in the stomach is called chyme.

9. Small Intestine
 Small intestines are roughly 7 meters long.
 Lining of intestine walls has finger-like
projections called villi, to increase surface
area.
 The villi are covered in microvilli which
furthered increase surface are for
absorption.

10.  Nutrients from the food pass into the
bloodstream through the walls of the small
intestine.
 Secretes digestive enzymes.
 Absorbs:
80% ingested water
Vitamins
Carbohydrates
Proteins
Lipids

11. Large Intestine
 About 1.5 meters long.
 Absorbs nutrients left behind by the small
intestines.
 The end of the large intestine is the
rectum(short term storage which hold
feces before it is expelled).

12. Accessory Organs- The Glands
 Not part of the path of ingested food, but play
critical role in digestion.
 Includes: Liver, gall bladder, and pancreas.

13. Functions:
1. Bacterial digestion and fermentation of
carbohydrates.
2. Absorbs additional water.
3. Concentrates wastes.

14. Liver
 Directly affects digestion by producing
bile.
Bile aids in the digestion of fat.
Filters out toxins and waste including
drug, alcohol and poisons.

15. Gall Bladder
 Stores bile from the liver,
releases it in to the small
intestine.
 Fatty diets can cause the
formation of gallstones.

16. Pancreas
 Produces digestives enzymes to
digests fats, proteins and
carbohydrates.
 Regulates blood sugar by
producing insulin.

17. Effects of Exercises on
Digestive System
1. Improve blood flow
2. Relieve stress
3. Regulate weight
4. Speed up metabolism
5. Increase breathing and heart rate

18. Exercises to Improve Digestion
 Walking(20 to 30 minutes daily)
 Cycling
 Sit-ups
 Push-ups
 Deep Breathing
 Sports
 Yoga

19. Thank you