Digestive system -Basic introduction

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: 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 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

14. Common GIT layers

15. 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

16. 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 .

17. 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 .

18. 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.

19. 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

20. MUSCULAR LAYER

21. 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

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