Chapter 32: The Digestive System

Stomach

10 inch long, J shaped organ constructed of three layers of strong muscle tissue, which lies just beneath the diaphragm. Inner lining is thick and lots of folds. Can hold half a gallon of food and liquid.

Esophagus

10 inches, made of smooth muscle. Two layers, inner layer forms circles around esophagus, outer layer runs longitudinally. Pushes food into stomach

Proctoscope

3 inch long scope used to examine the lower rectum and anal canal. For hemorrhoids, polyps, fissures, fistulas and abscesses.

Gastric

35 million gastric glands in the stomach lining which produce hydrochloric acid and several enzymes.

Digestive process

4 phases; ingestion, digestion, absorption and elimination

Rectum

6-8 inches long. Serves as a collecting area for the remains of digestion.

Cardiac sphincter

A circular muscle that controls the upper opening of the stomach. Dilates and allows food to enter and closes. One way opening.

Enzyme

A complex chemical substance produced by the body, found primarily in the digestive juices, that acts upon food substances to break them down for absorption

Mesentary

A fan shaped fold of tissue that is attached to the posterior abdominal wall.

Digestive

A group of organs that changes food that has been eaten into a form that can be used by the body's cell. AKA gastrointestinal tract/system

Insulin

A hormone secreted by the islets of langerhans in the pancreas

Anal canal

A narrow passageway 1 inch long, extends from rectum to the anus. Both ends controlled by sphincter muscles. Internal; involuntary, external;voluntary

Appendicitis

A painful, inflammatory process caused by a substance which irritates the lining. General abdominal pain then localized to RLQ (McBurney's point). Only surgical removal. NEVER use abdominal heat, enemas or laxatives to reduce risk of perforation. On right side w/ knees flexed reduced discomfort

Reflux

A return or backward flow

Vermiform appendix

A small projection which extends from the cecum. A worm shaped structure, easily filled, drained slowly.

Small intestine

A tube about 1 inch in diameter and 20 feet in length. Completes digestive process and absorbs nutrients from chyme. 3 sections; Duodenum, jejunum and ileum.

Villous adenoma

A type of polyp that is malignant and invasive

Canines

AKA cuspids. Side teeth. Pointed to puncture and tear

Bicuspids

AKA premolars. Back teeth. For grinding and crushing.

Digestion

Activity performed by the organs of the digestive system, the process of which food is broken down mechanically and chemically in GI tract and converted to absorbable form to be used by cells

Colon

After digestion receives by ileocecal valve; useful nutrients, and other substances absorbed from the chyme, waste products, any indigestible material and excess water. 5 feet long, 2 in. diameter. AKA Large intestine. Frames abdomen. No villi, only capillaries.

Colonoscopy

An examination to view the entire large intestine using a flexible fiberoptic scope. Do one every 10 years for age 50+. Done while patient is sedated and placed on left side.

Sigmoidoscopy

An examination to view the lower portion of the sigmoid and rectum through a 10-12 inch sigmoidoscope.

Fistula

An exudate which develop an escape route into rectum, anal canal or skin surface.

Nausea

An inclination to vomit

Peptic Ulcer

An ulcer in the stomach that is caused by acid. AKA gastric ulcer.

Occult blood test

Analysis of the feces to detect small amounts of bleeding from the intestinal tract. Brighter blood; closer to rectum. Smeared on slide and read in 1 min. if blue then blood.

Colostomy

Artificial opening of the colon allowing fecal material to be excreted from abdominal wall. Classified based on portion of colon involved. Temporary or permanent. No control over gas or stool expulsion.

Pyloric sphincter

At the end of the stomach, allows chyme to spurt through the sphincter into the small intestine.

Deciduous

Baby teeth. Appear at 6 months. Exchanged gradually for permanent teeth at age 6.

Upper GI series

Barium swallow initially then 16-20 oz of additional barium. X-rays at specific periods for further evaluation. Stomach is compressed. Patient rotated to several positions. Aids in Dx for; gastric ulcers, tumors, strictures of sphincters, inflammation of lining, motility irregularities, duodenal ulcers, tumors, filling defects.

Transverse

Begins at hepatic flexure and extends in a loop across abdominal cavity to a point below spleen, the splenic flexure.

Descending

Begins at the splenic flexure and extends downward along left side of abdomen until it reaches edge of the pelvic cavity. Smaller in diameter. Firmly anchored.

Stool

Bowel movement, feces

Ulcerative Colitis

Chronic inflammatory disease that affects the mucosa of the colon. Begins in sigmoid and rectum then upward. Does not involve small intestine. Mostly young adults, females. Prime symptom is recurrent bloody diarrhea.

Cirrhosis

Chronic liver disease-destruction of liver cells- impaired blood and lymph circulation. GI tract signs then nosebleeds, bleeding gums, anemia. Liver enlarged, jaundice, collection of fluid in abdomen. HTN in portal system-esophageal varices-rupture and bleed. Blood test or liver biopsy to Dx. -Cause-malnutrition w/ alcohol, hepatitis or duct disease which suppresses bile flow.

Irritable bowel syndrome

Chronic or periodic diarrhea and alternating constipation. AKA spastic colon. Symptoms; lower abdominal pain relieved by passing gas, or defecation, stools soft and contain mucus Cause; physiologic stress, or ingestion of irritants, abuse of laxatives, food poisoning, lactose intolerance, colon cancer, diverticular disease.

Fissure of the anus

Crack or tear in the lining of anus. Small drop of blood. May develop into swelling at lower end-sentinel pile. May heal or become chronic. Cause; passing large, hard stool

Hemorrhoids

Dilated veins in the mucosa of the anal canal and lower portion of rectum which contain vertical folds and mucous membrane. Symptoms; painless, intermittent bleeding, itching, if blood trapped then thrombosis-rectal pain and lump. Cause; long periods of sitting or standing, diarrhea, constipation, vomiting, coughing, hepatitis, alcoholism, loss of muscle tone Treatment; regulate bowel movements, limit sitting time on toilet, increase water intake, raw fruits/veggies and fiber, apply local heat

Varices

Dilated, tortuous veins in the lower section of the esophagus. Symptoms; fluid enters abdominal cavity causing ascites, hemorrhage, bloody emesis and stools. Cause; HTN in portal vein. Treatment; inserted tube for pressure to control bleeding, instill iced salt water, drug to control bleeding, surgical bypass to correct venous flow

Pepsin

Enzyme that digests milk curds from the rennin

Lipase

Enzyme that splits certain fats.

Rennin

Enzyme which curdles milk

Fats

Excellent source of energy. 1 oz three times more calories than 1 oz. of carbs. Excess amount is stored if not used for energy.

Salivary glands

Excrete saliva. Three pairs; parotid, submandibular and sublingual.

Mouth

First place of digestion where food enters. Held in the oral cavity.

Duodenum

First section of small intestine. C-Shaped, 9 inches long. Prone to ulcers (duodenal ulcers).

Cecum

First segment of the large intestine. A small pouchlike segment of the colon.

Saliva

Fluid excreted by the salivary glands. Contains enzyme (chemical) called ptyalin which begins breakdown of carbohydrates into sugar. Provides moisture that enables taste buds to perceive sensations of; sweet, sour, etc. Aids in cleansing teeth.

Rugae

Folds in the stomach lining

Lower GI Series

For viewing of entire large intestine. Barium as enema. Outlines interior wall of colon for detection of mucosal changes, tumors, polyps, ulcerated sites, diverticulitis, structural irregularities.

Common bile duct

Formed by the cystic and hepatic duct. Empties bile directly into duodenum to be added to chyme.

Incisors

Front teeth. Bite food with sharp edges

Cholelithiasis

Gallstones from the gallbladder. Expelled into cystic duct where they become lodged

Flatus

Gas

GERD

Gastroesophageal Reflux Disease. Backflow of gastric and sometimes duodenal contents. Symptoms; heartburn, esophageal spasms. Cause; faulty lower esophageal sphincter, hiatal hernia, anything that lower the LES pressure

Hepatitis Type A

Highly contagious, self limiting, transmitted by fecal oral route, sudden symptoms

Hepatitis

Inflammation and infection of the liver that can lead to cell destruction and death. Stage 1 symptoms; fatigue, malaise, headache, anorexia, sensitivity to light, sore throat, cough, nausea, vomit, frequent fever, liver and lymph node enlargement-disappear when jaundice Stage 2 symptoms; Begun when urine dark, stool clay colored, sclera and skin is yellow, mild weight loss, liver enlarged, spleen and cervical nodes swell. Stage 3 symptoms; Lasts 2-6 weeks. Full recovery in 6 months Blood test reveals positive if drawn early in stages.

Crohn's disease

Inflammation of any portion of the GI tract, most common in the terminal ileum. Involves all layers of intestinal wall, leads to edema, ulceration, narrowing and formation of abscesses and fistulas. Symptoms; pain, cramp, tenderness in RLQ, flatulence, nausea, fever and diarrhea, bloody stools. Cause; unknown, maybe allergies or immune disorders, obstruction of lymphatics or infection Dx; increased white blood cells, decreased hemoglobin Treatment; mainly symptomatic, dietary supplements, steroids, antibacterial, anti inflammatory, antibiotics, corticosteroids, lifestyle changes

Gastroenteritis

Inflammation of stomach and intestine-intestinal flu, traveler's diarrhea, food poisoning. Gone within few days, no risk unless very young, old and generally debilitated. Symptoms; fever, nausea, abdominal cramping, diarrhea and vomit, malaise, gurgling/splashing over intestines.

Colitis

Inflammation of the colon. Can be acute, or chronic

Pancreatitis

Inflammation of the pancreas. Enzymes produced and excreted into the duct remain and digest pancreatic tissue. Can cause diabetes if insulin producing cells are destroyed Symptoms; epigastric pain, severe then pain, persistent vomiting, rigid abdomen, rales, tachycardia, fever Cause; alcoholism. trauma, reaction to Rx and pancreatic carcinoma, duodenal ulcer.

Pruritus ani

Itching of the area surrounding the anus, associated with irritation and burning.

Liver

Largest gland in the body. Below the diaphragm in the RUQ, extends into ULQ. Secretes bile 1 pint/day. Stores glycogen, processes proteins from amino acids and either stores or burns fat. Manufactures fibrinogen, prothrombin, and other substances required for blood clotting. Produces antibodies and gets rid of toxins.

Pancreas

Lies behind the stomach with its head in the curve of the duodenum. A gland that secretes substances in two ways. Exocrine; through ducts and Endocrine; ductless. Secretes pancreatic juice (contains 3 enzymes to 3 types of nutrients) into duodenum. Secretes insulin into bloodstream.

Anorectal Abscess and Fistula

Local infection-collection of exudate in soft tissue. Throbbing, painful, lump. Can be from sharp object in feces which contains bacteria then infection. Need surgical intervention.

Colorectal Cancer

Malignancy of the colon or rectum. 3 most common cancer. -Symptoms; right side-black tarry stools, anemia, abdominal aching, pressure, cramps, weakness, fatigue, dyspnea, vertigo, diarrhea, anorexia, weight loss, vomi. Left side-obstruction earlier, rectal bleeding, abdominal fullness, cramp, rectal pressure, diarrhea, ribbon/pencil shaped stool, bright red blood. First symptom is change in bowel habits. -Cause; unknown -Treatment; Surgery to remove tumor, chemo, radiation

Polyp

Mass of tissue caused by overgrowth of upper epithelial cells of the mucosal membrane of the GI tract.

Villi

Millions of microscopic structures which project from the lining of the major part of the small intestine. Swing back and forth to keep chyme mixed with digestive juices. Each one equipped with blood capillaries and lacteal which absorb nutrients, minerals, water, some fats, all carbs, proteins in form of sugar and amino acids. Many fats through lacteal

Main organs of GI tract

Mouth, pharynx, esophagus, stomach, small intestine, and large intestine

Tongue

Moves food around within the mouth bringing it into contact with teeth. A muscle. Surface contains taste buds located within papillae projections

Stenosis

Narrowing or constriction of a passage or opening

Proteins

Obtained from plant and animal sources, not stored in by the body. Eat daily to build and repair cells and tissue.

Ulcer

Open sore. In the stomach caused by excess hydrochloric acid for a length of time.

Anus

Opening from the body.

Chyme

Partially digested food in the stomach, semiliquid. Forms in 3-5 hours after eating.

Fecal

Pertaining to feces (stool, bowel movement)

Paralytic ileus

Physiologic intestinal obstruction usually in small intestine. Peristalsis reduced or absent. Cause; manipulation of bowel during abdominal surgery or effects of anesthesia, ileus disappears in 2-3 days.

Diverticulitis

Presence of bulging pouches in the wall of the GI tract where lining pushed into surrounding muscle. Most common in Sigmoid colon. Symptoms; irregular bowel movements, LLQ abdominal pain, nausea, flatus, low grade fever, increase WBCs. Cause; high degree of internal pressure and area of weakness in intestinal wall. Less common with natural foods and fibers. Treatment; prevent constipation, then surgery

Hernia

Protrusion of an internal organ through a natural opening in the body wall.

Bowel

Refers to intestines

Diarrhea

Repeated passage of unformed waste. Serious in infants and small children-excessive loss of body fluid. Cause; bacteria, virus or amebic organism. Poor diet, toxic substances, foods like prunes.

Herniorrhaphy

Replaces the contents of the sac within the abdominal cavity and closes the opening in the case of a strangulated hernia.

Sigmoid

S shaped section of the colon when it enters the pelvic cavity. Extends from the left iliac crest over and back to join the rectum.

Jejunum

Second segment of small intestine. 8 feet in length. Suspended in the abdominal cavity by mesentary

Hydrochloric acid

Secreted by the gastric glands in the stomach. Mixed into the bolus while stomach is churning. Excess amount can lead to an ulcer. Does not burn stomach because of mucus. Unites with protein to form another chemical, which is then split by pepsin

Bile

Secreted by the liver. Unconcentrated is; bitter, yellow-orange liquid that is required to digest fats. Composed of water and contains pigment from red blood cells that have been destroyed. Pigment is changed in intestines and excreted in fecal matter. Concentrated; bitter and green-yellow.

Ascending

Section of the large intestine. Joins the Cecum at the level of the ileocecal valve and continues upward along right side of the abdomen to hepatic flexure. Larger in diameter than descending.

Hepatitis Type C

Silent at first then chronic that causes liver to scar, transmitted through blood and body fluids. Can be completely without symptoms.

Constipation

Sluggish bowel action. Dry, hard and infrequent bowel movements. Need proper diet, adequate fluid intake and exercise to prevent.

Gallbladder

Small sac attached to the underside of the liver. For concentration and storage of bile.

Peristalsis

Smooth, involuntary muscle action which maintains the movement of food through the body after it is swallowed.

Choledocholiatiasis

Stones in the common bile duct. Blocks bile from exiting the gallbladder or liver. Bile is reabsorbed into bloodstream causing jaundice.

Carbohydrates

Supply 2/3 of the energy calories needed each day

Ileostomy

Surgical opening of the ileum. Allows chyme of the small intestine to empty through the abdominal wall. Similar to colostomy by chyme is liquid and highly caustic to skin because of digestive juices.

Appendectomy

Surgical removal of the appendix.

Hemorrhoidectomy

Surgical removal of the dilated vein and the surrounding stretched mucosa

Cholecystectomy

Surgical removal of the gallbladder.

Accessory Organs of GI tract

Teeth, salivary glands, tongue, liver, gallbladder, and pancreas

Bolus

The combination of mashed food substances and saliva.

Alimentary canal

The connecting chain of organs to the digestive system

Hepatic duct

The duct from the liver

Ileocecal valve

The junction of ileum and large intestine. Allows chyme to enter cecum and prohibits return to ileum.

Ileum

Third segment of the small intestine. 12 feet long. Suspended by mesentery. Reduced to 1/2 in. diameter by the time it joins large intestine in RLQ

Vomit

To expel the contents of the stomach through the mouth

Defecate

To pass stool or move bowels

Barium Swallow

Used for diagnosing function or condition of esophagus. Radiopaque liquid swallowed while action of esophagus observed by fluoroscope. For dysphagia, hiatus hernia, diverticulosis, varices, strictures, tumors, ulcers.

Cystic duct

Used for gallbladder to empty its contents

Hepatitis Type B

Very contagious, high mortality rate, vaccine available, transmitted by ways other than mouth, insidious symptoms. No cure

Gastroscopy

Viewing of the esophagus, stomach, and upper duodenum through flexible scope that is lighted by fiber optics. Local anesthetic in back of throat and sedative, swallow scope.

Absorption

Vital function of the small intestine, primarily in jejunum and decreasing toward end of ileum. Accomplished through villi.

Emesis

Vomiting. Occurs when contraction of the abdominal muscles, forcefully squeeze the stomach as it is pushed downward by the diaphragm. This pressure and reverse peristaltic waves the contents are forced out.

Incontinent

When a person cannot control the anus. Defecation occurs whenever the nerve impulse is triggered

Impaction

When a person is too weak to expel the contents of the rectum. Material becomes more and more solid as fluid content is lost and mass becomes such a size where it cannot be expelled. Requires manual breakup and enemas.

Strangulated hernia

When additional intestines enter the sac or contents become twisted or trapped, interfering with circulation of blood to intestine. Requires surgery

Hiatus

When the diaphragm allows part of the stomach to move up into the chest cavity through the opening for the esophagus. Three types; sliding, rolling (paraesophageal) and mixed. Rolling kind; full feeling in chest, angina like pain, requires surgery. Sliding kind; heartburn, chest pain, distention and spasms of stomach, difficulty swallowing or ulcer

Inguinal hernia

When the surrounding structure of fibrous tissue, the fascia, becomes weak it allows a loop of small intestine to protrude through the ring, following path of spermatic cord. Often extends into scrotum when standing. Can be reduced or pushed back into place.

Jaundice

Yellow discoloration of the sclera, mucosa and skin.