digestive system objectives: 1.what are the nutrients that the body uses 2.what is the purpose of...
TRANSCRIPT
Digestive System
Objectives:1. What are the nutrients that the body uses2. What is the purpose of digestion3. Identify the organs of the Digestive System
Nutrients of the Body
Carbohydrates – Provide energy for the body– Fiber – helps food move through your digestive
tract– Starch – Complex carbohydrate– Sugar – Simple carbohydrate. It is the building
block of all carbohydrates
Nutrients of the Body
Fats - Provides energy for the body when carbohydrates are not available
– Fatty acids and glycerol – building blocks of fats
– Saturated – from animals mainly– Unsaturated – from plants mainly
Nutrients of the Body
Proteins - Provides energy for the body when fats and carbohydrates are not available.
– Used to build and repair the body– Amino acids – building blocks of proteins
Nutrients of the Body
• Minerals -- Helps your body function properly (ex. Keeps muscle, bones, nerves healthy)
• Vitamins – needed for chemical reaction to occur in the body (ex. Aids in blood clotting)
• Water – chemical reactions of the body take place in water.
Digestive System• Purpose of the digestive system is to fuel the
body with energy from nutrients.
• Types of Digestion– Mechanical – physical action of breaking
food down into smaller pieces (done in mouth and stomach)
– Chemical – food is broken down into the essential nutrients the body can use with the help of chemicals such as enzymes
“Lock and Key” System
+ =
carbohydrate enzyme
Sugars
“Lock and Key” System
• Enzymes– Chemicals that help break down substances
(foods)– Often end in “ase”
• Examples:– Amylase carbohydrates– Protease proteins– Lipase fats (lipids)
What’s missing?
Organs of the Digestive SystemMouth Salivary glands
• Food is mechanically digested with the help of the teeth and tongue
• secretes saliva into the mouth (chemical)
• Food is chemically digested with the help of saliva and the enzyme amylase
• Food doesn’t enter the salivary glands
• Saliva breaks down carbohydrates into sugars
• Chyme is the name of the chewed food in your mouth
Organs of the Digestive SystemEsophagus Stomach
• transports food to the stomach (mechanical)
• produces gastric juice to breakdown proteins into amino acids (chemical)
• Smooth muscles push food through the digestive tract, this is known as peristalsis
• A layer of mucus protects the stomach lining from gastric juice
• Churns food with strong muscles (mechanical)
Organs of the Digestive SystemLiver Gall Bladder
• produces bile that chemically digests food in the small intestine
• small sac underneath the liver which stores bile - mechanical
• Bile breaks down fats into fatty acids
• Food doesn‘t enter the liver
• Food doesn’t enter the liver
Organs of the Digestive System
Pancreas• Known as the “super gland”
• Produces pancreatic juice that chemically digests food in the small intestine
• Pancreatic juice breaks down carbohydrates, fats, and proteins
• Food doesn’t enter the pancreas
Organs of the Digestive System
Small Intestine Villi
• most important digestive organ (22-24ft long); absorption of nutrients through villi - mechanical
• Fingerlike projections inside small intestine; increase the surface area for nutrient absorption
• Bile and pancreatic juice digest food in the small intestine - chemical
• Absorption = mechanical digestion
• Intestinal juice breaks down carbohydrates and protein – chemical
Organs of the Digestive System
Large Intestine• Water is reabsorbed in the large intestine (3-4 ft. long) -
mechanical
• Waste products are collected in the large intestine (feces) and are stored in the rectum - mechanical
• Wastes are expelled from the body through the anus - mechanical
• No nutrients are absorbed in the large intestine