Key Terms

Bilirubin

orange- yellow pigment formed during destruction of erythrocutes that is taken up by liver cells and eventually excreted in the feces. Excessive bilirubin can cause jaundice, which indicates liver damage/ disease

Bolus

Mass of masticated food ready for swallowing

Exocrine

Type of gland that secretes its products through excretory ducts to the surface of an organ or tissue or into a vessel

Sphincter

Circular band of muscle fibers that constricts a passage or closes a natural opening of the body.

Triglycerides

Organic compound, a true fat, that is made of one glycerol and three fatty acids

Oral cavity

Receptacle for food. Formed by the cheeks (bucca), lips, teeth, tongue, and hard and soft palates.

Bolus

Mechanically and chemically (saliva) broken down food. To be swallowed.

Dentin

Main structure of the tooth. Beneath the enamel

Pulp

Innermost part of the tooth.Contains nerves and blood vessels

Gums (gingiva)

Pink fleshy tissue where teeth are embedded.

Tongue

Manipulates bolus during chewing, moves bolus to the back of the mouth for swallowing (deglutition). Aids in speech production and taste.

Hard palate

Anterior portion of roof of mouth

Soft palate

Posterior portion of roof of mouth. Continuous with hard palate. Forms a partition between the mouth and nasopharynx.

Pharynx

the throat. Funnel shaped passageway to the respiratory and GI tracts. Provides a resonating chamber for speech sounds. Lowest portion of the pharynx divides in two. One leads to lungs, other leads to trachea (GI tract)

Uvula

v shaped structure that guides food

Trachea

Leads to lungs

Esophagus

Leads to stomach from pharynx.

Epiglottis

Flap that folds back to cover the trachea; it guides food to the esophagus

Stomach

Saclike structure located in LUQ of the abdominal cavity. Food reservoir that continues mechanical and chemical digestion. It extends from the esophagus to the duodenum (first part of the small intestine)

Lower esophageal (cardiac) sphincter

Terminal portion of the esophagus. Composed of muscle fibers that constrict once food has passed into the stomach. Prevents stomach contents from regurgitating back into the esophagus.

Fundus

Upper portion of the stomach. Mainly a storage area.

Body (of stomach)

Large central portion of stomach. Mainly a storage area

Pylorus

Funnel-shaped terminal portion of the stomach. Where most digestion takes place.

Rugae

Macroscopic longitudinal folds that line the interior of the stomach. Composed of mucous membranes. Gradually unfolds as the stomach fills. Holds digestive glands that produce hydrochloric acid and enzymes.

Chyme

Semiliquid produced as a product of chemical and mechanical churning of the stomach.

Pyloric sphincter

Regulates the speed and movement of chyme into the duodenum (beginning of small intestine). Prevents backflow.

Peristalsis

Coordinated and rhythmic muscle contractions that propel food through the entire GI tract.

Duodenum

Uppermost segment of the small intestine. 10 inches long

Jejunum

Second segment of the small intestine. 8 feet long

Ileum

Third segment of the small intestine. 12 feet long.

Villi

Microscopic finger-like projections that absorb nutrients in chyme. The nutrients then enter the bloodstream and lymphatic system for distribution through the rest of the body.

Ileocecal valve

Sphincter muscle that allowed undigested or unabsorbed material from the small intestine to pass into the large intestine and eventually be excreted from the body. Located at the terminal end of the small intestine.

Cecum

Small pouch that comprises the first 2 or 3 inches of the large intestine. Hangs inferiorly to the ileocecal valve. First part of the colon.

Appendix

Small wormlike structure. No apparent function. May become inflamed and infected when blocked. Appendectomy may be performed if appendicitis occurs.

Transverse colon

Colon continues across the abdomen to the left side. (Splenic flexure) Curves beneath the lower end of the spleen; this leads to the descending colon.

Descending colon

Continues from transverse colon towards the sigmoid colon and rectum.

Rectum

Connects sigmoid colon and anus (last part of the GI tract).

ulcer

circumscribed open sore on skin or mucous membranes of the body

gastrointestinal endoscopy

Visual examination of the gastrointestinal tract using a flexible fiberoptic instrument with a magnifying lens and a light source (endoscope) to identify abnormalities, including bleeding, ulcerations, and tumors

Hepatitis panel

panel of blood tests that identifies the specific virus- hepatitis A (HAV), hepatitis B (HBV), or hepatitis C (HCV)- that is causing hepatitis by testing serums using antibodies to each of these antigens

Liver function tests (LFTs)

Group of blood tests that evaluate liver injury, liver function, and conditions commonly associated with the biliary tract.

Serum bilirubin

Measurement of the level of bilirubin in the blood .

Stool culture

Test to identify microorganisms or parasites present in feces that are causing a gastrointestinal infection.

Stool guaiac

Test that applies a substance called guiac to a stool sample to detect the presence of occult (hidden) blood in the feces; also called hemoccult

Lower gastrointestinal series

Radiographic images of the rectum and colon following administration of barium into the rectum; also called lower GI series or barium enema

Oral cholecystography (OCG)

Radiographic images taken of the gallbladder after administration of a contrast material containing iodine, usually in the form of a tablet

Magnetic resonance cholangiopancreatography (MRCP)

Special MRI technique that produces detailed images of the hepatobiliary and pancreatic systems, including the liver, gallbladder, bile ducts, pancreas, and pancreatic duct.

abdominal US

US visualization of the abdominal aorta, liver, gallbladder, bile ducts, pancreas, kidneys, ureters, and bladder. Diagnose and locate cysts, tumors, and malformations; document the progression of various diseases; guide the insertion of instruments during surgical procedures

endoscopic US

Endoscope is inserted via the mouth or rectum. It then emits US waves that produce images of organs and structures.

Anastomosis

Surgical joining of two ducts, vessels, or bowel segments to allow flow from one to another.

Ileorectal

Surgical connection of the ilem and rectum after total colectomy, as is sometimes performed in the treatment of ulcerative colitis.

Intestinal (surgery)

Surgical connection of two portions of the intestines

Appendectomy

Excision of a diseased appendix using an open or laparoscopic procedure.

Open (appendectomy procedure)

Excision of a diseased appendix through a 2” to 3” incision in the right lower quadrant of the abdomen.

Laparoscopic (appendectomy procedure)

Minimally invasive appendectomy using three small abdominal incisions while monitoring an enlarged image of the surgical site projected on a monitor

Bariatric surgery

Group of procedures that treat morbid obesity, a condition that arises from severe accumulation of excess weight as fatty tissue, and the resultant health problems

Vertical banded gastroplasty

Bariatric surgery that involves vertical stapling of the upper stomach near the esophagus to reduce it to a small pouch and insertion of a band that restricts food consumption and delays its passage from the pouch, causing a feeling of fullness

Roux-en-Y gastric bypass (RGB)

Bariatric surgery that involves stapling the stomach to decrease its size and then shortening the jejunum and connecting it to the small stomach pouch, causing the base of the duodenum leading from the nonfunctioning portion of the stomach to form a Y configuration, which decreases the pathway of food through the intestine, thus reducing the absorption of calories and fats; also called gastric bypass with gastroenterostomy

Colostomy

Surgeon forms an opening (stoma) by drawing the healthy end of the colon through an incision in the anterior abdominal wall and suturing it into place

Lithotripsy

Procedure for crushing a stone and eliminating its fragments surgically or using ultrasonic shock waves

Extrocorporal shock-wave lithotripsy (ESWL)

Use of shock waves as a noninvasive method to break up stones in the gallbladder or biliary ducts

Paracentesis

Procedure to remove fluid from the abdomen using a long, thin needle inserted through the belly; also called abdominocentesis. Fluid makeup assists with diagnosis

Polypectomy

Excision of a polyp. Abnormal or cancerous cells may be detected post excision.

Nasogastric intubation

Insertion of a nasogastric tube through the nose into the stomach to relieve gastric distention by removing gas, food, or fluids; or obtain a specimen for laboratory analysis

Antacids

Counteract or neutralize acidity, usually in the stomach. Calcium carbonate, aluminum hydroxide, and magnesium hydroxide

Antidiarrheals

controls loose stools and relieve diarrhea by absorbing excess water in the bowel or slowing peristalsis in the intestinal tract

Antiemetics

control nausea and vomiting by blocking nerve impulses to the vomiting center of the brain. Some antiemetics act by hastening movement of food through the digestive tract.

Antispasmodics

Decrease gastrointestinal (GI) spasms by slowing peristalsis and motility throughout the GI tract. Help treat IBS, spastic colon, and diverticulitis.

Histamine-2 (H₂) blockers

Inhibit secretion of stomach acid from the gastric cells by blocking the H₂ receptor. Treat acid reflux and gastric or duodenal ulcers.

Laxatives

Treat constipation by increasing peristaltic activity in the large intestine or increasing water and electrolyte secretion into the bowel to induce defecation.

Proton pump inhibitors

Suppress basal and stimulated acid production by inhibiting the acid pump in the gastric cells. Treat gastric and duodenal ulcers; and acid reflux. These drugs are more potent acid inhibitors than the H₂ blockers