The Digestive System From Food to Nutrients

The Digestive System - Definition The function of the digestive system is to break down food into nutrients and absorb them into the blood stream where they can be delivered to all cells of the body to use in cellular respiration.

From Food to Nutrients – Pizza!

The Mouth Teeth break food into smaller pieces Saliva is secreted into the mouth from the salivary glands to help lubricate the food Mouth forms a bolus (ball) of food that can be swallowed easily

The Pharynx – Don’t Choke! Part of both digestive and respiratory system When swallowing, a small flap called the epiglottis blocks the opening of your windpipe Allows food to go down the esophagus “Down the wrong tube”

The Esophagus 10 inches long, stretchy pipe Transports food from mouth to stomach Food doesn’t just slide down, muscles contract to push the food down – peristalsis 2-3 seconds to go down

The Stomach Stretchy, J-shaped sac Stomach is like a mixer – slowly mashing together the food, breaking it into smaller pieces (stomach muscles) Gastric juices help break the food down

The Small Intestine – Not So Small! 1½ - 2 inches thick, 22 ft long (stretched out) Food spends about 4 hours in the S.I. 3 organs secrete liquid into the beginning of the S.I. to help break down food even more: Pancreas Liver Gallbladder

The Pancreas Secretes juices into the small intestine to help break down fats and proteins

The Liver and the Gallbladder Liver produces digestive juice called bile Gallbladder stores bile from liver until needed Bile secreted into the small intestine to helps absorb fats

Absorption As food travels through the small intestine, it is broken down more and more into elements that can be used by the body Nutrients are absorbed into the blood stream to make their way to your cells

The Large Intestine 3-4 inches thick, 5 ft long After the nutrients get absorbed in your S.I., there’s stuff left over that your body can’t digest - waste L.I. absorbs water as waste passes through (solidifying) Very little digestion occurs

The Appendix Tiny tube with closed end coming off the L.I. Has no function!

The Last Stop Last part of the large intestine is the rectum Solidified Storage for waste until it is released from our bodies through the anus

Very Important! The digestive system is very important because without it, your body couldn’t get the nutrients it needs in order to grow big and strong!