Topic 3.0 Healthy human function depends on a variety of interacting and reacting systems
Organ Systems Organ systems must have the ability to to changes within and outside of your body to maintain life Organ systems on each other Organ systems work together, or, as a single unit to carry out all the functions that are vital to your survival
Topic 3.1 the digestive system (Pages 127-130) Living organisms need to survive We obtain OUR energy through (sugars and starches), (fats and oils), and We NEED our digestive system to break down all of these! Our digestive system breaks down the food we eat into small usable particles that can be used by our cells and travel through our digestive system
Types of Digestion Digestion The physical breakdown of food into very small pieces. Biting, chewing, stomach turning Digestion The breakdown of large particles into smaller particles by substances called» Enzymes substances created in the body to carry out chemical digestion SALIVA, GASTRIC JUICES (mucus, hydrochloric acid, and digestive enzymes), BILE water
Function of Digestive System FUNCTION: break down food pieces into much smaller particles so they can be and throughout the body. tissue lines all the organs. REMEMBER THIS IS YOUR SKIN!!!!!!!
Let s explore what the digestive system consists of.
Mouth Digestion begins at the, with the mechanical digestion of your food The teeth mechanically digest by grinding it and mixing it with 3 pairs of salivary glands located within tissue surrounding your mouth Saliva contains to moisten the food, making it easier to swallow Saliva contains enzymes Adding saliva to the food forms
Esophagus -The is a flap of skin that covers the windpipe so that food will not enter the lungs. -The food is pushed down the by contractions of muscle tissue. -This muscle tissue looks like long bands that push the food all the way down through wave like movement. This movement is called. -When you take too big of a bite, this is Where you feel discomfort
Stomach The muscular wall of the stomach churns the food back and forth, while mixing it with secretions from the wall of the stomach, known as. Gastric Juice is composed of mucus, hydrochloric acid, water and digestive enzymes The hydrochloric acid, along with enzymes, digests proteins into smaller particles The mucus helps to prevent the gastric juices from digesting the stomach itself The stomach slowly releases the food, which is now a liquid, into the small intestine
SMALL INTESTINE The food then enters the small intestine where chemical digestion continues with digestive enzymes added from the pancreas. These new enzymes, along with the enzymes from the small intestine, complete the breakdown of starches and proteins. The produces, which is stored in the. The gall bladder sends the bile into the small intestine to help break up lipids/fatty acids into small droplets.
Small Intestine Once food is broken down small enough it is absorbed through the small intestine wall into the blood stream meters long Food not broken down passes to the intestine
Villi in small intestine Villi are finger like projections inside the small intestine They increase the surface area so more nutrients can be absorbed into the blood stream
Each villi is covered with epithelial tissue (shown in pink) Nutrients get absorbed into the epithelial tissue then the nutrients are transferred into the blood stream The blood stream takes the nutrients to where they are needed by cells
Digestion is complete Large intestine Water, vitamins and minerals are absorbed Food takes 12 hours to 2 days to pass through the small and large intestine
Last stop before unused particles are expelled from the body Rectum
STRUCTURE WHAT HAPPENS MOUTH -mechanical digestion using your teeth. -chemical digestion using an enzyme called salivary amylase (produced in 3 glands around your mouth). -salivary enzyme digests large starch molecules into smaller sugar molecules. ESOPHAGUS STOMACH SMALL INTESTINE -swallowed food moves down the esophagus in wave-like movement called peristalsis caused by the contraction of muscle tissue. -the muscular walls of the stomach churn food as gastric juices are secreted. Hydrochloric acid and the enzymes chemically digest the protein into smaller pieces. -mucus prevents the gastric juices from digesting itself. -digestion is complete. -absorption of water along with some vitamins and minerals. -undigested food is formed into feces and collected in the rectum. LARGE INTESTINE -digestion is complete. -absorption of water along with some vitamins and minerals. -undigested food is formed into feces and collected in the rectum.
Check and Reflect 1. Imagine that you ve eaten a cheeseburger. Describe the path of the burger through your digestive system and the mechanical and chemical digestion that occurs to the food 2. For each of the terms below explain the relationship that exists digestion, enzymes nutrients, villi digestion, peristalsis 3. Make a chart like the one below and use information that you have learned to fill it in. Organ Mechanical Digestion Chemical Digestion