The The Digestive Digestive SystemSystem

Functions of the Digestive SystemFunctions of the Digestive System

1. Extracts nutrients through chemical & mechanical digestion2. Absorbs nutrients from food3. Removes undigested wastes4. Maintains water and chemical balances

Path of Food Through Path of Food Through the Digestive Systemthe Digestive System

Mouth Mouth (includes salivary gland, teeth and tongue)

Esophagus Esophagus (tube connecting mouth to stomach)

Stomach Stomach (contains hydrochloric acid)

Small Intestine Small Intestine (longest structure – absorbs nutrients)

Large intestine (colon) Large intestine (colon) (water absorption)

Rectum Rectum (storage of non-digested waste)

Anus Anus (removal of non-digested waste)

Accessory Organs Accessory Organs (Help with digestion, but food does not pass through them)(Help with digestion, but food does not pass through them)

PancreasPancreas – produces digestive enzymesproduces digestive enzymes which break down carbohydrates, proteins and fat

LiverLiver – produces bileproduces bile which helps break down fat

Gall Bladder Gall Bladder – bile is storedbile is stored in this organ

Spleen Spleen – helps transport and transform nutrientstransform nutrients

Appendix Appendix – contains massive amounts of bacteria which aid in digestionaid in digestion

Salivary Glands Salivary Glands – – produces salivaproduces saliva which breaks down starch into sugars

Digestive EnzymesDigestive Enzymes(don’t need to memorize..just informative)(don’t need to memorize..just informative)

SalivaSalivaAmylaseAmylase – breaks down starchstarch

Stomach Stomach PepsinPepsin – breaks down proteinsproteins

Pancreas Pancreas AmylaseAmylaseTrypsinTrypsin – breaks down proteinsproteins into peptidesLipase Lipase – breaks down fatsfats (lipids)NucleaseNuclease – breaks down nucleic acidsnucleic acids into nucleotides

Small IntestineSmall IntestineMaltaseMaltase – breaks down maltosemaltose into glucoseSucraseSucrase – breaks down sucrosesucrose into glucosePeptidasePeptidase – breaks down peptidespeptides into amino acidsNucleaseNuclease – breaks down nucleotidesnucleotides into sugar and nitrogen bases

Role of Villi Role of Villi

The villi line the small intestineline the small intestine ..

They are microscopic, finger-like projectionsmicroscopic, finger-like projections ..

They increase the surface areaincrease the surface area of the small intestine

allowing for more absorption of nutrientsmore absorption of nutrients. Sugars and

amino acids enter capillaries and fatty acids enter the

lymphatic vessels inside the villi.

What is peristalsis?What is peristalsis?

The wave-like contractions of smooth muscle in the The wave-like contractions of smooth muscle in the digestive tract which propels food through the esophagus, digestive tract which propels food through the esophagus, stomach, small and large intestines, and rectum.stomach, small and large intestines, and rectum.

Diseases of the Digestive SystemDiseases of the Digestive SystemAppendicitisAppendicitis - A blockage inside of the appendix causes

appendicitis. The blockage leads to increased pressure, problems with blood flow and inflammation. If the blockage is not treated, the appendix can break open and leak infection into the body.

Diverticulosis and Diverticulitis Diverticulosis and Diverticulitis - diverticula are small pouches that bulge outward through the colon, or Large intestine. If you have these pouches, you have diverticulosis. It the pouches become infected or inflame you have diverticulitis. The maincause is a diet low in fiber..

Peptic UlcerPeptic Ulcer - a peptic ulcer is a sore in the lining of your stomach or your duodenum, the first part of our small intestine. A burning stomach pain is the most common symptom.