Explained about basic of Digestive system

1. Human Anatomy and Physiology-II
Digestive system
(Basic of Digestive system)
Mr N.JEGAN
Associate Professor
K.M.COLLEGE OF PHARMACY.
MADURAI.

2. Introduction
• Digestion is defined as the process by which food
is broken down into simple chemical substances
that can be absorbed and used as nutrients by the
body.
Food Digestion Simple chemical substance
Absorption
Nutrients
Body tissues

3. Functions of Digestive system

4. Functions of digestive system
1.Ingestion
2.Propulsion
3.Digestion
4.Absorbtion
5.Excretion

5. Functions of digestive system
1.Ingestion.
This is the process of taking food into the
alimentary tract.

6. 2. Propulsion.
This moves the contents along the alimentary
tract.

7. 3.Digestion.
This consists of:
A) Mechanical breakdown of food
e.g. mastication (chewing)
B) Chemical digestion of food
by enzymes present in the secretions produced by glands
and accessory organs of the digestive system.

8. 4.Absorption.
This is the process by which
digested food substances pass
through the walls of some
organs of the alimentary canal
into the blood for circulation
round the body

9. 5.Excretion
Food substances which have been eaten but
cannot be digested and absorbed are excreted by
the bowel as faeces.

10. Digestive system organs

11. GI tract is formed by two types of
organs
1. Primary digestive organs:
Primary digestive organs are the organs
where actual digestion takes place.
2. Accessory digestive organs:
which help primary digestive organs in
the process of digestion

12. Primary digestive organs
1. Mouth
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
6. Large intestine.

13. Accessory digestive organs
1.Teeth
2. Tongue
3. Salivary glands
4. Exocrine part of pancreas
5. Liver
6. Gallbladder

15. Common GIT layers

16. Digestive system-common structure
• Digestive system is made up of gastrointestinal
tract (GI tract) or alimentary canal and accessory
organs
• GI tract is a tubular structure extending from the
mouth up to anus, with a length of about 30 feet

17. Common GI tract -Layers
It is formed by four layers which are from inside out:
1. Mucus layer
2. Submucus layer
3. Muscular layer
4. Serous or fibrous layer.

19. Mucus layer
• Mucus layer is the innermost layer of the wall
of GI tract.
• It is also called gastrointestinal mucosa or
mucus membrane
• It is lined with stratified squamous and
columnar epithelial cells
• It secrete Mucus it keep the GIT in wet.

20. Submucus layer
• This layer consists of loose connective tissue
with some elastic fibres
• Blood vessels, lymphatic vessels and nerve
plexus are present in this layer.

21. MUSCULAR LAYER
It consist of 2 layers of smooth muscle
1. circular layer - inner layer
2. longitudinal layer - outer layer
But in stomach ,it have 3 layers of muscles
1 . oblique layer - inner layer
2. Circular layer - Middle layer
3. longitudinal layer - outer layer

22. MUSCULAR LAYER

23. SEROUS OR FIBROUS LAYER
• Outermost layer of the wall of GI tract is
either serous or fibrous in nature
• It is formed by connective tissue and
mesoepithelial cells
• It covers stomach, small intestine and large
intestine

24. Thanking you