Digestive System Notes

Transcription

1 Name: Date: Digestive System Notes Digestion: Digestion breaks food molecules down into smaller molecules It is necessary to make smaller molecules because these nutrients need to be used by CELLS. Only small molecules can pass through the cell membrane and into the cell so it can be used. EX: We break starch ( a large molecules) down into glucose (a small molecule that can cross cell membranes) so our cells can do respiration and make energy! What are each of the following broken down into??? Proteins Starch Lipids Carbohydrates Steps of Digestion: Ingestion Digestions Absorption Excretion Types of Digestion: Mechanical physically breaking food down into smaller pieces o This creates more surface area, so enzymes can get to more molecules Chemical use of chemicals and enzymes to break food into substances that can be absorbed

2 Mouth: Teeth are used for mechanical digestion to break the food into smaller pieces, so it can be easily swallowed. Saliva contains an enzyme (amylase) used in chemical digestion, which breaks down starches into simple sugars The tongue is your strongest muscle used to manipulate food during mastication Esophagus: The tube the food travels down to get to the stomach Peristalsis is the motion that pushes the food down the tube. The tube pinches off above the food pushing it toward the stomach You have an epiglottis that covers your esophagus while you are breathing and covers your trachea while you are swallowing This prevents food from going down the wrong tube Stomach: The stomach performs mechanical and chemical digestion of food. The stomach secretes a powerful acid (pepsin) that breaks food down It also churns mixing the food with the acid and breaking it down mechanically Chyme is the mixture of stomach acid (pepsin), broken down food, and saliva that flows from the stomach into the small intestine Duodenum: This is the first section of the small intestine, where most of the chemical digestion of carbohydrates, lipids, and proteins occurs Chyme is joined with enzymes from the liver and pancreas that reduce acidity of the chyme and chemically digest the food Small Intestine: The small intestine are covered in little finger like projections called villi Villi increase the surface area of the small intestine to increase absorption of nutrients The usable nutrients are removed from the chyme and travel across the villi into the blood vessels that are inside it Large Intestine: When the food arrives in the large intestine it is nutrient free The large intestine pulls any excess water out of the remaining indigestible material creating feces The large intestine is filled with bacteria that help our digestion process When the large intestine is not removing enough water, diarrhea will result When the large intestine removes too much water, constipation will occur Rectum: The rectum will store the feces until there is enough to pass out of the body When the rectum is full, you feel the urge to go to the bathroom There is a sphincter muscle at the bottom of the rectum called the anus This squeezes shut to keep feces in the rectum and expands to allow it out when passing a stool

3 Liver, Pancreas, and Gallbladder: The liver and pancreas secrete enzymes and digestive fluids that mix with the chyme in the duodenum The pancreas secretes a fluid to neutralize the acidity of the stomach acid The liver secretes bile, which is used to break down fatty acids (lipids) Bile is stored in the gall bladder Digestive Diseases: Diarrhea too much fluid in the bowel movements o Caused by the large intestine not removing enough water; Can be caused by viruses or bacteria o Can lead to dehydration and eventually death Constipation too much water being removed from the bowel movements o Can be caused by poor diet or not taking in enough water o Symptoms can be alleviated by taking laxatives Appendicitis - an infection of the appendix, usually remedied by removing the appendix GERD - heartburn; caused by stomach acid rising into the esophagus and burning the lining IBS - Irratable Bowel Syndrome; certain foods affect the lining of the intestines causing diarrhea Ulcers - when the stomach acid burns the stomach creating sores on the inside the stomach wall, can cause blood to move throught the digestive system creating blackish bowel movements Cirrhosis - when the liver cells start to die because they have been abused by poor diet or alcohol abuse; can be cured by getting a liver transplant Diverticulitis - small bulging sores anywhere in your intestinal tract; can be caused by certain food becoming lodged in the bowels Ulcerative Colitis - when the immune system attacks the bowels causing constant diarrhea Hemorrhoids - when a vein or artery in the anus protrude or swell; this can be caused by constipation or straining during deffication Celiac s - an allergy to gluten (found in many grains), causes rashes and diarrhea Lactose Intolerance - means your digestive system is not able to digest the lactose sugar found in milk

4 Name: Date: Digestive System Notes Digestion: Digestion breaks food molecules down into molecules It is necessary to make smaller molecules because these nutrients need to be used by. Only molecules can pass through the cell and into the cell so it can be used. EX: We break (a large molecules) down into (a small molecule that can cross cell membranes) so our cells can do and make energy! What are each of the following broken down into??? Proteins Starch Lipids Carbohydrates Steps of Digestion: Digestion Excretion

5 Types of Digestion: Mechanical breaking food down into smaller pieces o This creates more, so enzymes can get to more molecules Chemical use of chemicals and to break food into substances that can be Mouth: are used for digestion to break the food into smaller pieces, so it can be easily Saliva contains an (amylase) used in chemical digestion, which breaks down into The tongue is your strongest muscle used to manipulate food during mastication Esophagus: The the food travels down to get to the Peristalsis is the that pushes the food down the tube. The tube off above the food pushing it toward the stomach You have an that covers your esophagus while you are and covers your trachea while you are This food from going down the wrong tube Stomach: The stomach performs and digestion of food. The stomach secretes a powerful (pepsin) that breaks food down It also mixing the food with the and breaking it down is the mixture of stomach acid ( ), broken down, and that flows from the stomach into the Duodenum: This is the first section of the intestine, where most of the digestion of carbohydrates,, and proteins occurs

6 Chyme is joined with from the and that reduce of the chyme and chemically the food Small Intestine: The intestine are covered in little finger like projections called Villi increase the of the small intestine to increase absorption of nutrients The usable are removed from the and travel across the into the that are inside it Large Intestine: When the arrives in the large intestine it is The large intestine pulls any excess out of the remaining indigestible material creating The large intestine is filled with that help our digestion process When the large intestine is removing enough water, will result When the large intestine removes water, will occur Rectum: The rectum will the feces until there is enough to pass out of the body When the rectum is, you feel the to go to the bathroom There is a muscle at the bottom of the rectum called the This shut to keep feces in the and expands to allow it out when passing a Liver, Pancreas, and Gallbladder: The liver and pancreas secrete and digestive fluids that mix with the in the The pancreas secretes a fluid to the acidity of the stomach acid The liver secretes, which is used to break down (lipids) Bile is stored in the

7 Appendix: Is located near the junction of the and The appendix is a organ, which means it was once used but in size as it became less Some organisms use the appendix to help break down in very fibrous substances ( ) Digestive Diseases: Diarrhea too much in the bowel o Caused by the intestine removing enough water o Can be caused by, bacteria, etc. o Can lead to and eventually death Constipation too much water being from the bowel movements o Can be caused by poor or not taking in enough o Symptoms can be alleviated by taking Appendicitis - an infection of the appendix, usually remedied by removing the appendix GERD - heartburn; caused by stomach acid rising into the esophagus and burning the lining IBS - Irratable Bowel Syndrome; certain foods affect the lining of the intestines causing diarrhea Ulcers - when the stomach acid burns the stomach creating sores on the inside the stomach wall, can cause blood to move throught the digestive system creating blackish bowel movements Cirrhosis - when the liver cells start to die because they have been abused by poor diet or alcohol abuse; can be cured by getting a liver transplant Diverticulitis - small bulging sores anywhere in your intestinal tract; can be caused by certain food becoming lodged in the bowels Ulcerative Colitis - when the immune system attacks the bowels causing constant diarrhea Hemorrhoids - when a vein or artery in the anus protrude or swell; this can be caused by constipation or straining during deffication Celiac s - an allergy to gluten (found in many grains), causes rashes and diarrhea Lactose Intolerance - means your digestive system is not able to digest the lactose sugar found in milk