As the Stomach Churns Tuesday January 12, 2016 Objective: You will examine the different organs of the digestive system and investigate the difference between mechanical and chemical digestion. Homework: Finish BrainPop Worksheet(pg. 23a) Quiz on Friday, Jan. 22 Heart & Digestive Systems Classwork: Collect page 16a for grading BrainPop Worksheet(pg. 23a) Intro to Digestive System Digestion Notes Foldable (pg. 23b)
Not on foldable Digestive System Pre Assessement 1. What does your digestive system do? 2. What organs do you think help with digestion AND what do they do?
Not on foldable What is the function? Breaks down into usable nutrients. absorb nutrients get rid of solid waste
Digestive Foldable
Digestive System Notes for foldable Summarize notes for foldable
How is food broken down? Mechanical Digestion Chemical Digestion Mechanical vs Chemical Digestion Foldable
Mechanical Digestion Occurs in the mouth and stomach Teeth tears, grinds, breaks into smaller pieces Stomach muscles mix the stomach contents
Chemical Digestion Mouth saliva contains enzymes that break down carbohydrates (starches and sugars) An enzyme is a chemical that causes chemical reactions in other substances Stomach acids (ex. hydrochloric acid) dissolves and breaks food down Small Intestine
Chemical Digestion Most occurs in the small intestine!!!!
Main Parts Mouth/Salivary Glands Esophagus Stomach Small Intestines Large Intestines Accessory organs : Liver, pancreas and gall bladder
Occurs in the esophagus!
Small Intestine The majority of digestion takes place in the small intestine. This organ is not given its name by its length but by its diameter.
Absorption of Nutrients Most occurs in the small intestines by villi. Villi are fingerlike projections in the small intestines. Villi are surrounded by blood vessels (capillaries) Blood transports nutrients to the entire body
Large Intestine The large intestine stores the remaining digested food anywhere from 18 24 hours. The excess water is absorbed into the bloodstream before being removed as waste.
Accessory Organs Liver produces bile Bile is a chemical that helps the body break down fats cleans toxins from blood blood leaving small intestine goes directly to the liver Gall Bladder stores bile from the liver Bile is added to the small intestine Pancreas produces insulin that breaks down carbohydrates and regulates sugar levels Insulin lowers acid levels
Questions????
How does the mouth contribute to the process of digestion? The teeth grind and tear food and saliva contains enzymes that begin the chemical breakdown of food.
Explain how your stomach helps break down food. The stomach muscles churns and mixes food to continue the process of mechanical breakdown. Chemical digestion occurs as acids dissolve food into a liquid.
Explain the relationship between food and nutrients. After the food is broken down, we call the usable pieces nutrients. Examples of nutrients are water, proteins, fats, and carbohydrates.
What role(s) does your small intestine play in digestion? The small intestines is where most chemical digestion occurs. Most of the substances produced by the breakdown of food is absorbed into blood by villi in the small intestines.
Explain how the digestive and circulatory systems work together? The walls of the small intestine are lined with villi. These are surrounded by capillaries which absorb the nutrients into the bloodstream and send them to the body cells. (what does this remind you of)?
Why does blood travel to your liver before transporting nutrients to other parts of the body? Blood first travels to the liver to remove the toxins (poisons).