Digestive System Mrs. Morgan Biology

Digestive System

Mouth Where digestion begins Where digestion begins The lips, cheeks, and tongue are all involved in the process The lips, cheeks, and tongue are all involved in the process The teeth break down food physically The teeth break down food physically The 3 sets of salivary glands The 3 sets of salivary glands –Lubricate food –Break up starch –Dissolve some foods –Attack dangerous microorganisms Source:

Pharynx Also known as the throat Also known as the throat Area between the mouth and esophagus Area between the mouth and esophagus Passage for both food and oxygen Passage for both food and oxygen A bolus is a ball of food A bolus is a ball of food Source:

Esophagus A tube that is approximately 23-25cm long that connects the mouth and stomach A tube that is approximately 23-25cm long that connects the mouth and stomach The epiglottis is a flap of cartilage that covers the windpipe when swallowing The epiglottis is a flap of cartilage that covers the windpipe when swallowing Peristalsis is rhythmic muscular contractions that moves food from mouth to the stomach Peristalsis is rhythmic muscular contractions that moves food from mouth to the stomach Source:

Stomach A “J” shaped organ A “J” shaped organ Used for storage and it regulates the flow of food into the small intestine Used for storage and it regulates the flow of food into the small intestine Holds 1 liter of food Holds 1 liter of food Digestion in the stomach take between 2-5 hours Digestion in the stomach take between 2-5 hours Contains pepsin (digests protein) and hydrochloric acid (helps break down food) Contains pepsin (digests protein) and hydrochloric acid (helps break down food) Source:

Pancreas Approximately 12.5cm long x 2.5cm thick Approximately 12.5cm long x 2.5cm thick Main role is to secrete 3 enzymes into the small intestine Main role is to secrete 3 enzymes into the small intestine These enzymes break down carbohydrates, proteins, and fats These enzymes break down carbohydrates, proteins, and fats Source: undagroundmilli.wordpress.com

Gallbladder Approximately 7-10cm long Approximately 7-10cm long Main function is to store bile and then injects it into the small intestine Main function is to store bile and then injects it into the small intestine Bile breaks down fat molecules into small fat molecules Bile breaks down fat molecules into small fat molecules Gallstones form when there is too much cholesterol in the bile. They can cause pain when they block ducts. Gallstones form when there is too much cholesterol in the bile. They can cause pain when they block ducts. Source:

Liver It is the largest organ in the body…weighs about 3lbs It is the largest organ in the body…weighs about 3lbs The liver's main job is to filter the blood coming from the digestive tract, before passing it to the rest of the body. The liver also detoxifies chemicals and metabolizes drugs. As it does so, the liver secretes bile that ends up back in the intestines. The liver also makes proteins important for blood clotting and other functions. The liver's main job is to filter the blood coming from the digestive tract, before passing it to the rest of the body. The liver also detoxifies chemicals and metabolizes drugs. As it does so, the liver secretes bile that ends up back in the intestines. The liver also makes proteins important for blood clotting and other functions. Hepatitis: Inflammation of the liver, usually caused by viruses like hepatitis A, B, and C. Hepatitis can have non-infectious causes too, including heavy drinking, drugs, allergic reactions, or obesity. Hepatitis Source: webmd.com

Small Intestine 6.35m long x 2.5cm diameter 6.35m long x 2.5cm diameter Most of digestion and absorption of nutrients occurs Most of digestion and absorption of nutrients occurs It can take 3-6 hours for a meal to pass from one end to the other…depends on what you eat It can take 3-6 hours for a meal to pass from one end to the other…depends on what you eat Source:

Large Intestine Also known as the colon Also known as the colon 1.5m long x 6.5cm diameter 1.5m long x 6.5cm diameter Main function is the absorption of water Main function is the absorption of water Removes water from undigested food  feces Removes water from undigested food  feces Source:

Anus The end The end It has 2 sets of sphincters (ringlike muscle that normally maintains constriction of a body passage or orifice and that relaxes as required by normal physiological functioning) It has 2 sets of sphincters (ringlike muscle that normally maintains constriction of a body passage or orifice and that relaxes as required by normal physiological functioning) Diarrhea happens when too little water is absorbed Diarrhea happens when too little water is absorbed Constipation is slow movement of fecal matter; too much water is absorbed Constipation is slow movement of fecal matter; too much water is absorbed Source: digestive.niddk.nih.govdigestive.niddk.nih.gov

Digestive System Facts Organs that make up the digestive tract: – –Mouth – –Esophagus – –Stomach – –Small IntestineSmall Intestine – –Large Intestine (colon) – –Rectum – –Anus Organs that help with digestion but are not part of the digestive tract: – –Tongue – –Glands in the mouth that make saliva – –Pancreas – –Liver – –Gallbladder

Digestive System Facts An adult esophagus (also called gullet) ranges from 10 to 14 inches in length, and 1 inch in diameter. We make 1 to 3 pints of saliva a day. Muscles contract in waves to move the food down the esophagus. This means that food would get to a person's stomach, even if they were standing on their head. It takes your mouth, esophagus, stomach, small intestine, large intestine, gallbladder, pancreas and liver just to digest a glass of milk. An adults stomach can hold approximately 1.5 liters of material. The stomach's wall is lined with three layers of powerful muscles. The average male will eat about 50 tons of food during his lifetime in order to sustain a weight of 150 pounds.

Digestive System Facts In the mouth, food is either cooled or warmed to a more suitable temperature. The liver performs more than 500 functions. The small intestine (pronounced in-test-in) is a long tube about 1 and a half to 2 inches around, and about 22 feet long. The large intestine is fatter than the small intestine at about 3 to 4 inches around, but shorter than the small intestine at about 5 feet long. A full grown horse?? Their coiled up intestines are 89 feet long. The digestive tract is like a long tube, approximately 30 feet long in total, through the middle of the body. It starts at the mouth, where food and drink enter the body, and finishes at the anus, where leftover food and wastes leave the body.

Digestive System Facts Within the colon, a typical person harbors more than 400 distinct species of bacteria. On average, the stomach produces 2 liters of Hydrochloric Acid (HCl) daily. After you eat, it takes usually between 24 and 72 hours in healthy adults for the complete process of digestion to occur. All the different varieties of food we eat are broken down by our digestive system and transported to every part of our body by our circulatory system. Food stays in your stomach for 2 to 3 hours. Source:

Digestive System

Quiz 1. The pharynx is also known as the a. epiglottisb. throatc. tonsils 2. What conducts food from the mouth to the stomach? a. esophagusb. epiglottisc. pharynx 3. What foods are broken down in the esophagus? 1. fats2. proteins3. carbohydrates a. none of the aboveb. all of the abovec. 1,2,3 4. What chemical does the liver produce that breaks down fat droplets? a. pepsinb. acidc. bile

5. What is the largest organ in the body? a. esophagusb. mouthc. liver d. stomache. pancreasf. rectum g. small intestineh. large intestine 6. TRUE/FALSE – The pancreas secretes digestive enzymes into the small intestine. 7. The pancreas makes 3 different enzymes that… a. help break down fats b. help break down carbohydrates c. help break down proteins d. all of the above e. none of the above

8. ______ is the small bag-like organ located under the liver that stores bile. 9. TRUE/FALSE – Most of the chemical digestion of food takes place in the small intestine. 10. What is the main job of the large intestine? 11. What digestive organ(s) move food through by peristalsis? 1. esophagus2. stomach3. liver 4. pancreas5. mouth6. large intestine a. 1 & 6b. Only 1c. 3 & 4 d. 2 & 6e. 3 & 5f. all of them