The Digestive System

Combining Forms Append/o appendix Appendic/o appendix Col/o colon Dent/o teeth Enter/o intestine Esophag/o esophagus Gastr/o stomach Gingiv/o gums Gloss/o tongue Hepat/o liver Lingu/o tongue Myc/o fungus Odont/o teeth Or/o mouth Proct/o anus/ rectum Sial/o saliva Stomat/o mouth

Prefixes A- / an- without or not Dia- through, across Dys- bad, painful, difficult Endo- within Hyper- excessive, above, more Hypo- below, under, less Ortho- straight Sub- below

Suffixes -al pertaining to -algia pain -dynia pain -ectomy removal of -emesis vomiting -ist specialist -itis inflammation -logist specialist in the study -megaly enlargement -oma tumor -orexia appetite -osis abnormal condition -pathy disease -pepsia digestion -phagia swallowing -plasty surgical repair -rrhea flow or discharge -scope instrument to view -scopy to view

Abbreviations / Terms GI gastrointestinal Defecation removal of solid waste from the body Deglutition swallowing Emulsification breakdown of large lipid molecules into smaller ones Haustral Churning muscular contraction pushing matter into next pouch Maceration churning within the stomach to soak bolus in enzymes Mastication chewing Peristalsis wave-like motion

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 (feces) from the body

The Digestive Organs Mouth Pharynx Esophagus Stomach Small Intestines Large Intestines Rectum Anus

Mouth Ingestion- eating Mechanical digestion Chemical digestion Teeth Mastication Chemical digestion Salivary glands- secrete salivary amylase digestion of carbohydrates begins Mechanical +Chemical digestion Softens food and creates a bolus (semi-solid food lump)

Teeth (accessory organ) Four types of teeth Incisors- front 4 top and bottom Cuspids- also known as canines for their pointed shape Bicuspids- also known as premolars and have a flattened crown Molars- back teeth for crushing and grinding food “typical” tooth parts Crown/neck/root- from top to bottom Enamel/dentin/pulp- from outside in Gingiva- gums Peridontal ligament/cementum- hold teeth to jaw

Pharynx (throat) Deglutition A passageway for food, liquids, and air

Esophagus Muscular tube located behind the trachea About 10 inches long Peristalsis Transports bolus from the pharynx to the stomach

Stomach J-shaped pouch located below the diaphragm Fundus Rugue Sphincter Mechanical digestion Maceration Chemical digestion gastric juice secretion Hydrochloric acid- breaks down bolus into chyme (liquefied food mixed with enzymes) Pepsin- breaks down protein

Small Intestines Mechanical digestion Chemical digestion Peristalsis continues Absorption of nutrients is highly active Chemical digestion Bile- made in the liver, stored in the gallbladder; emulsifies fat Trypsin- made in pancreas to break down protein Amylase- made in pancreas to break down carbohydrates Lipase- made in pancreas to break down fats Three divisions of the small intestines: Duodenum – first portion of the small intestine where the majority of chemical digestion occurs. Jejunum – middle portion of the small intestine where the majority of absorption of nutrients occurs. Ileum – final portion of where absorption occurs.

Large Intestines Also called the colon Mechanical digestion Cecum Ascending colon, transverse colon, descending colon, sigmoid colon Rectum Anus Mechanical digestion Haustral churning Absorption- water, vitamins, electrolytes, production of vitamin K; changes chyme to feces

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 Mechanical digestion Defecation

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.

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, stricture 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.

Inguinal Hernia Inguinal hernias occur when a part of the intestine protrudes through a weak point or tear in the abdominal wall. This protrusion creates a bulge which can be painful. Some inguinal hernias occur at birth when the abdominal lining does not close properly. Other inguinal hernias occur later in life when muscles weaken or deteriorate. The most common treatment is surgery.