Digestive System – pgs. 45-50 Directions: Read SILENTLY pages 45-50 in your Human Biology Textbook. Write the following information/definitions in your notes. 1. Function of Digestive system 2. Nutrients 3. Peristalsis 4. Two types of digestion AND how they work 5. Moving through the digestive system: Write the function and definition of the following main organs in the digestive system. Mouth Esophagus Stomach Small intestine Large Intestine Liver Gallbladder Pancreas

Homework - Advanced Science Periods 2 &3 Using your notes from the Human Body Textbook Pages 45-50 answer each of the critical thinking questions on a separate piece of paper with your name and period number on it. Homework Due Thursday, 3/29 Critical Thinking Question 1: Based off of what you learned about digestion, does an antacid deal with mechanical or chemical digestion? Critical Thinking Question 2: You have just swallowed a bite of apple. Describe what happens as the apple moves through the digestive system. Include information about what happens to the material in the apple.

Homework – General Science Periods 6 & 7 Answer all of the questions on a separate sheet of paper with your name and period number on it. Due Thursday, 3/29 List three Functions of the Digestive System Give one example of mechanical digestion Give one example of chemical digestion How does your stomach process food?

Assignment In your compositing book, using the diagram given in class, draw a picture of the digestive system and label all parts of the system.

Digestive System – moves and breaks down food. The Digestive System Digestive System – moves and breaks down food. Digestion – the process of breaking down food into smaller and usable materials. Nutrients – important substances that enable the body to move, grow, and maintain homeostasis. Proteins, carbohydrates, fats, and water are some of the nutrients your body needs. Brainpop: http://www.brainpop.com/health/bodysystems/digestivesystem/

Moving and Breaking Down Food Peristalsis – The muscular action of material moving through the digestive system by wave-like action of smooth muscles.

Two Types of Digestion Mechanical Digestion – The physical process of breaking food into smaller pieces. Ex. Chewing food, stomach mashing and pounding food during peristalsis. Chemical Digestion – Chemical changes actually change the food into different substances. Ex: Chewing a cracker – the cracker is broken into smaller pieces and the saliva in our mouth produces a chemical change – the starches in the cracker are changed to sugars.

Moving Through the Digestive System: Digestion. Mouth and Esophagus – both mechanical and chemical digestion take place in the mouth. Stomach – Smooth muscles mix and mash the food. Chemicals break down the food – some chemicals are acids. These acids are so strong that they could eat through our stomach. To prevent this, the cells of the stomach’s lining are replaced every 3 days, and the stomach is coated with a thick mucus.

Continuing the Digestion . . . Small Intestine – partially digested food moves into the small intestine. The food is broken into nutrients – which are mostly absorbed into the small intestine. Villi (small structures in the small intestine) contain folds that absorb the nutrients and then are transported by the circulatory system. Large Intestine – this is where water and other nutrients are absorbed from the digested material. Most of the solid material that remains is compacted and stored and eventually eliminated through the rectum.

Other Organs in the Digestion process . . . Liver – Very important organ and the largest internal organ of the body – located just above your stomach. The liver filters blood and cleans it. It also produces bile which is important because it breaks down fats. Gallbladder – pear-shaped sac connected to the liver. Bile produced in the liver is stored and concentrated in the gallbladder, then secreted into the small intestine. Pancreas – Located between the stomach and the small intestine, the pancreas produces chemicals that are needed as materials moves between the two. The chemicals produced by the pancreas are extremely important for digesting food. Without these chemicals your body would die of starvation, even if you had plenty of food in your system – your body could not process and use the food without the pancreas. Liver