Award in Nutrition for Healthy Living Lesson 1: Structure and Function of the Digestive System

Unit 1 Food Groups and Digestion COPYRIGHT © PURE TRAINING AND DEVELOPMENT

Lesson 1 Learning Objectives Understand the structure and functions of the digestive system Outline the roles of the digestive organs Describe movement through the digestive system Describe the role of digestive enzymes Describe digestion of carbohydrates, fats and proteins COPYRIGHT © PURE TRAINING AND DEVELOPMENT

Functions of Digestive System Breakdown of foods Extraction of nutrients for use around the body Extraction of water for use around the body COPYRIGHT © PURE TRAINING AND DEVELOPMENT

Structure of Digestive System COPYRIGHT © PURE TRAINING AND DEVELOPMENT Mouth Oesophagus Stomach Duodenum Small intestine Large intestine (including colon and rectum)

Role of Digestive Organs - Mouth COPYRIGHT © PURE TRAINING AND DEVELOPMENT Teeth and saliva work to breakdown food Saliva contains the ENZYME SALIVARY AMYLASE Breaks starch in to sugars Passes easier along the oesophagus

Role of Digestive Organs – Oesophagus COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE Muscular tube Leads the pharynx to the stomach First key organ in the digestion process FUNCTION Carry food to stomach Moves via muscular contraction Known as peristalsis

COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE Rounded and hollow Innermost layer (mucosa – mucous membrane) Elastic – expanding and relaxing Sphincters at top and bottom prevent back flow and ensure control Food enters from oesophagus and leaves into the duodenum (1st part of the small intestine) Role of Digestive Organs – Stomach

COPYRIGHT © PURE TRAINING AND DEVELOPMENT FUNCTION Digests proteins and fats through enzymatic reactions Gastric juices breaks down food further Absorbs alcohol When food is partly digested, the mass is known as chyme Chyme moves from stomach to small intestine Role of Digestive Organs – Stomach

Role of Digestive Organs – Small Intestine COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE 7 metres long 3 sections (duodenum, jejunum and ileum) Inner wall covered in villi, tiny finger like projections which increase area for absorption FUNCTION Completes the chemical digestion process Absorption of nutrients take place here Absorbed through the villi into blood Site for water absorption too

Role of Digestive Organs - Pancreas COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE & FUNCTION Behind the stomach Works with digestive and endocrine system to produce enzymes Pancreatic enzymes break down CHO, protein and fat Break down food, stores insulin and glucagon (glycogen back to glucose)

Role of Digestive Organs – Gall Bladder COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE Pear shaped Stores bile made from the liver Bile used to digest food Bile emulsifies fat and allows for absorption of fats

Role of Digestive Organs – Duodenum COPYRIGHT © PURE TRAINING AND DEVELOPMENT Monitors content of chyme via sensors Proteins and fats cause hormone to released bile from gall bladder Bile reaches duodenum where is breaks fats down by enzyme pancreatic lipase Absorption of vitamins, minerals and nutrients takes place here

Role of Digestive Organs – Jejunum COPYRIGHT © PURE TRAINING AND DEVELOPMENT Section where the villi line the walls The majority of absorption is carried out in this section Simple sugars, water soluble vitamins and amino acids Final stages of absorption occur Role of Digestive Organs – Ileum

Role of Digestive Organs COPYRIGHT © PURE TRAINING AND DEVELOPMENT Duodenum Jejunum Ileum

Role of Digestive Organs – Large Intestine COPYRIGHT © PURE TRAINING AND DEVELOPMENT STRUCTURE 1.5m long Four sections: caecum, appendix, colon and rectum Deals with waste FUNCTIONS Formation of Vit B and K Reabsorb remaining water Eliminate waste and undigested foods Results in faeces – passed to colon

Peristalsis COPYRIGHT © PURE TRAINING AND DEVELOPMENT Term used for the movement of food through digestive system A series of smooth muscular contractions Muscular Wall Contraction Chyme

Digestive Enzymes COPYRIGHT © PURE TRAINING AND DEVELOPMENT OrganSecretionAction Mouth Salivary Glands Salivary amylaseConverts starch into sugars Pancreas and DuodenumLipase Coverts fats into fatty acids StomachPepsinDigestion of proteins

Summary Video External Video available in Resources Section COPYRIGHT © PURE TRAINING AND DEVELOPMENT

Summary COPYRIGHT © PURE TRAINING AND DEVELOPMENT Identified the structure of the digestive system Determined the route which food takes in order to be digested Identified that the small intestine has 3 sections and each are important for the absorption of nutrients Highlighted the key enzymes responsible for digestion Described the process of digestion of carbohydrates, proteins and fats.

ANY QUESTIONS? If you need any support please do not hesitate to get in contact with your mentor. COPYRIGHT © PURE TRAINING AND DEVELOPMENT

Activities Pure Training and Development © 2014 Complete the Quiz ‘Quiz Yourself from Lesson 1’ Label the blank Digestive System Diagram Download/Print any resources you need for Lesson 2 Take a 15 minute break

End of Lesson 1 Pure Training and Development © 2014 Complete your quiz…