The Digestive System

Related Medical Terminology• GI – Gastro-intestinal

• Colo- Colon

• Cheilo – lips

• Gastro – stomach

• Gingivo – gums

• -ia – condition

• Stomato – mouth

• Hepato – liver

• Procto – rectum

• - ‘itis – inflammation

The Basic Functions of the Digestive System

• Ingestion-taking nutrients into the body, i.e., eating

• Digestion-the mechanical and chemical breakdown of food into a usable form

• Absorption-the movement of molecules through the mucosal lining of the stomach and small intestine, and into the blood

• Excretion-the removal of solid waste from the body

• Sphincters-circular muscles that contract and move food through the GI tract.

The Digestive Organs• Mouth• Pharynx • Larynx• Esophagus• Stomach• Small Intestines – 3

duodenum, jejunum, ileum

• Large Intestines – 4ascending, transverse, descending, sigmoid

• Rectum• Anus

Class ActivityTravel Brochure

• Divide into groups of three or four students. Assign each group a "location" of the digestive system. For example, one group has "stomach," while another has "small intestine." Each group will design a travel brochure for their "location." Include pertinent information, such as the overall appearance of the location, the activities that occur there and the imports (what comes in) and exports (what goes out). Include possible dangers or complications that can occur at your specific location. Be creative with your descriptions and have fun with the explanations.

MouthDigestion starts here!!!

• Mechanical digestion-chewing or

“mastication”

• Chemical digestion-digestion of carbohydrates

Pharynx• Also called the throat

Nasopharynx

Oropharynx

Laryngopharynx

• A passageway for food, liquids, and air

Esophagus• Muscular tube located behind the

trachea

• About 10 inches long

• Transports food from the pharynx to the stomach

• Upper and Lower esophageal sphincters

Stomach• J-shaped pouch located below the

diaphragm

• Chemical digestion of protein occurs in the stomach due to gastric juice secretion

• Mechanical digestion occurs in the stomach due to maceration (churning). Three layers of muscles in the stomach create the movement of maceration.

Small Intestines• Chemical digestion of nutrients and

absorption of nutrients is completed in the small intestines (ave. 22.5 feet in adults)

• Three divisions of the small intestines:– Duodenum – first portion (10-15”) where the

majority of chemical digestion occurs (Brunner’s Glands- mucus/enzymes)

– Jejunum – middle portion (8’) where the majority of absorption of nutrients occurs.

– Ileum – final portion (12’) where absorption occurs.

Large Intestines• The large intestines are the last part of

the digestive system.

• Absorption of water, vitamins, electrolytes, production of vitamin K, and formation of feces occurs in the large intestines

• Ascending, Transverse, Descending, Sigmoid colons

Rectum• The last portion of the large intestine

which functions as a temporary storage of solid wastes before excretion

Anus• The final portion of the rectum where

solid waste is excreted from the body

Diseases and Disorders of the Digestive System

Colon Cancer• Most of the cancers of the large intestine are believed

to have developed from polyps (benign tumors). • Cancer of the colon and rectum, also called colorectal

cancer can invade and damage adjacent tissues and organs.

• Symptoms include fatigue, weakness, shortness of breath, change in bowel habits including diarrhea or constipation, red or dark blood in stool, weight loss, abdominal pain, cramps, or bloating.

• Surgery is the most common treatment for colon cancer.

Chron’s Disease• Chron’s disease is an ongoing disorder that causes

inflammation of the digestive tract.• The disease can affect any area of the GI tract, from

the mouth to the anus, but it most commonly affects the lower part of the small intestine, the ileum.

• The swelling extends deep into the lining of the affected organ.

• The swelling can cause pain and can make the intestines empty frequently, resulting in diarrhea.

• Chron’s disease may be caused by an abnormally functioning immune system.

• Treatment includes prescription medications, nutritional supplements, surgery, or a combination of these.

• There is no cure.

from ehealthmd.com/chron’s disease

• Compromised nutrition, even malnutrition, is a constant threat to an individual with Crohn's disease. This is because the disease creates a vicious cycle:

• Fever and diarrhea cause a loss of appetite.

• Fever, by raising the body's metabolic rate, adds to the need for caloric energy.

• Diarrhea can lead to dehydration and temporary lactose intolerance (the inability to digest milk sugars).

• Lactose intolerance causes milk sugars to ferment in the colon, leading to cramps and more diarrhea.

• Lactose intolerance can also indirectly lead to calcium deficiency, which in turn can lead to the loss of bone density called osteoporosis. This side effect can be especially prevalent among those being treated with corticosteroids such as prednisone.

Celiac Disease• Celiac disease is a digestive disease that damages the

small intestine and interferes with absorption of nutrients from food.

• People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley.

• When people with celiac disease eat foods or use products that contain gluten, their immune system responds by damaging the small intestine.

• Celiac disease is an autoimmune disease that is genetic.

• The most common symptoms include pain in the digestive system or other parts of the body.

• The only know treatment is a gluten-free diet.

Appendicitis

• Appendicitis, inflammation of the appendix, is the most common surgical disease.

• It results from the obstruction of the opening to the appendix by a mass, structure or infection.

• Symptoms of appendicitis include generalized abdominal pain, pain localized in the lower right abdomen, nausea, vomiting, possibly fever, and an elevated white blood cell count.

• Treatment involves the removal of the appendix and antibiotics.