Health Occupations

Digestive System

Digestive/Gastrointestinal System

 Consists of organs making up ALIMENTARY CANAL – From mouth to anus – 30 feet long – Not a sterile system – open to environment at both ends – Process includes • Transportation of food & wastes • Physical & chemical breakdown of food • Absorption of digested food • Elimination of wastes • Helps to maintain proper amounts of water, nutrients, electrolytes

Definitions

 Digestion – Process of changing food into a usable substance  Absorption – Transfer of nutrients into the blood

Organs of the Digestive System

1.

Mouth A. Food enters alimentary canal – INGESTION B. Teeth – bite & chew food to physically break it down C. Tongue – tastes, chews (MASTICATION), & helps swallow (DEGLUTITION) D. Hard palate – anterior roof of mouth E. Soft palate – posterior roof of mouth, not attached to bone

F. Uvula – small piece of tissue at back to mouth to prevent food from entering nasal cavity during chewing G. Process of mastication 1. As food is chewed – mixes with saliva 2. 3 salivary glands – secrete amylase to begin chemical breakdown of food (enzyme – protein that increases the rate of chemical activity in body) a. Parotid b. Sublingual c. Submandibular

2.

3.

H. Begins the transformation of starch to sugar I. Bolus – portion of food, mixed with saliva, that is swallowed Pharynx – 3 parts – nasopharnyx, oropharynx, laryngopharynx A. Food passes through oropharynx from mouth to esophagus B. Epiglottis closes so you don’t inhale food/drink Esophagus A. Tube like structure carrying food from mouth to stomach B. Peristalsis – movement of food down esophagus with slow, wavelike movements

4.

Stomach A. Bolus mixes with HCL & enzymes pepsin & lipase to become CHYME (semifluid material) 1. Pepsin – starts protein digestion 2. Lipase – starts fat digestion 3. HCL – kills bacteria, helps iron absorption, activates pepsin 4. Rennin – in infants, helps milk digestion, not present in adults 5. Direct absorption – alcohol, glucose, some drugs via stomach walls

6. Cardiac sphincter – valve preventing chyme from flowing back into esophagus 7. Pyloric sphincter – controls flow of chyme into intestines. Takes 1-4 hours for stomach to empty into intestines

5. Small Intestine

A.

B.

Coiled section about 20 feet long, 1 inch in diameter 3 sections 1. Duodenum – 1 st 9-10 inches where bile from gall bladder & liver & pancreatic juices enter through ducts 2. Jejunum – 8 feet in length, middle section 3. Ileum – final 12 feet, connects with large intestine at cecum

Ileum

A.

B.

C.

D.

E.

F.

Ileocecal valve – separates ileum & cecum, prevents food from returning to ileum Digestion completed in small intestine, products are absorbed into bloodstream Intestinal juices produced by small intestine, contains enzymes that break down sugars into simple forms (maltase, sucrase, lactase) Also has pepsidases – protein digestion Steapsin – aids in fat digestion Bile – from liver & gall bladder to physically break down fats

Ileum

G.

H.

I.

Pancreatic enzymes – complete process of breaking down food 1. Pancreatic amylase – sugar 2. Trypsin/chymotrypsin – proteins 3. Lipase/steapsin – fats Villi – small fingerlike projections lining walls of small intestine – contain capillaries & lacteals 1. Capillaries – absorb nutrients & carry to liver for storage or released into circulation 2. Lacteals – absorb fat & carry to thoracic duct of lymph system to be released into circulation Only wastes, indigestibles, & water are left

6. Large Intestine

A.

B.

Final section, 5 feet in length, 2 inches in diameter Functions 1. Absorb water & other nutrients 2. Stores indigestible materials before elimination 3. Synthesizes & absorbs B vitamins & Vitamin K by bacteria 4. Transports wastes out

C. Divided into a series of connected sections

1. Cecum – 1 st section, connected to ileum, contains appendix 2. Colon – 4 parts a. Ascending – up right side of body to lower liver b. Transverse – across abd below liver & stomach, above sm intestine c. Descending – down left side of body d. Sigmoid – S shaped section, joins with rectum

e. Rectum – final 6 – 8 inches, stores wastes & indigestibles f. Anal canal – narrow canal at end, opening into anus where wastes are expelled through

7. Peritoneum

A.

B.

C.

Flat serous membrane surrounding abdominal cavity Lubricates & prevents friction between organs Mesentary – fan-shaped projection of peritoneum that contains blood vessels & nerves 1. binds to abdominal organs to keep them in place

8. Accessary Organs

A.

Liver – largest gland in body 1. Located under diaphragm in RUQ 2. Secretes bile – emulsify fats & makes them water soluble to be absorbed 3. Stores sugar – glycogen, converts to glucose & released to bloodstream when extra sugar is needed 4. Stores iron & vitamins 5. Produces heparin, fibrinogen, & prothrombin – prevent clotting of blood 6. Detoxifies substances like alcohol & pesticides 7. Destroys bacteria taken into blood by intestine

B. Gallbladder

1.

2.

3.

Small muscular sac located under liver, attached by connective tissue Stores & concentrates bile (receives from liver) Contracts when bile is needed to emulsify fats, bile goes through the common bile duct & into duodenum

C. Pancreas

1.

2.

3.

4.

Gland located behind stomach Produces pancreatic juices – contain enzymes to digest food Pancreatic juices enter duodenum through pancreatic duct Produces insulin which regulates metabolism, burning of carbs to convert glucose to energy

Parotid gland Esophagus Cardiac sphincter Stomach Pancreas Transverse colon Descending colon Sigmoid colon Rectum Anus Appendix Cecum Ileum Ascending colon Duodenum Pyloric sphincter Gall bladder Liver Larynx Pharynx

Appendicitis

 Acute inflammation of appendix, usually from obstruction & infection  Symptoms – Generalized abd pain, later localizing in RLQ – N & V – Mild fever – Elevated WBC  If ruptures, infectious material spills into peritoneum & causes peritonitis  TX - appendectomy

Cholecystitis

 Inflammation of gallbladder where gallstones form (cholelithiasis)  Symptoms occur after fatty meal – Indigestion, N & V – Pain under ribcage, radiates to right shoulder   If gallstones block bile ducts, gallbladder can rupture Tx – low fat diet, lithotripsy, cholecystectomy

Cirrhosis

  Chronic destruction of liver cells with formation of fibrous connective & scar tissue Causes – – Hepatitis – Bile duct disease – Chemical toxins – Malnutrition associated with alcoholism  Symptoms – Liver enlargement – Anemia – Indigestion, N & V – Nosebleeds – Jaundice – Ascites

Cirrhosis

 Tx – – Prevent more damage to liver – Avoid alcohol – Good nutrition – Supplements – Rest – Infection prevention – Appropriate exercise

Constipation

 Fecal material remains in colon too long    Causes excessive reabsorption of water Stool – hard, dry, difficult to eliminate Causes – – Poor bowel habits – Chronic laxative use – Low fiber diet – Digestive diseases  TX – High fiber diet – Adequate fluids & exercise – Occasional laxatives

Diarrhea

 Condition with frequent watery stools  Causes – Infection – Stress – Diet – Irritated colon – Toxic substances – Very dangerous in young  Tx – Eliminating cause – Adequate fluids – Modifying diet

Diverticulitis

 Inflammation of diverticula (pouches that form in intestine as mucosal lining pushes through surrounding muscle)    Fecal material & bacteria become trapped in diverticula, creating inflammation Result – abscess formation or rupture Symptoms – vary with level of inflammation – Abd pain, N & V – Irregular BM – Flatus, constipation, diarrhea – Abd distension – Low grade fever

Diverticulitis

 Tx – Antibiotics – Stool softeners – Pain meds – surgery



Gastroenteritis

Inflammation of mucous membrane lining stomach & intestine  Causes – Food poisoning – Infection – toxins  Sx – Abd cramping, N & V – Fever & diarrhea  Tx – Rest, fluids – Antibiotics, IV – Meds to slow peristalsis

Hemorrhoids

  Painful, dilated or varicose veins of rectum or anus Causes – – Straining to defecate – Constipation – Pressure during pregnancy – Insufficient fluids – Laxative abuse – Prolonged sitting or standing

Hemorrhoids

 Sx – Pain – Itching – bleeding  Tx – High fiber diet – Increased fluids – Stool softeners – Sitz baths or warm moist compresses – hemorrhoidectomy

Hepatitis

 Viral inflammation of liver – Type A – highly contagious, transmitted in food or water contaminated by feces of infected person, vaccine available – Type B – transmitted by blood, can lead to chronic hepatitis or cirrhosis, vaccine available – Other strains – SX – fever, anorexia, N & V, fatigue, dark colored urine, clay-colored stools, enlarged liver, jaundice – TX – rest, diet high in protein & calories but low in fat, may need liver transplant

Hernia

  Rupture, occurring when internal organ pushes through a weakened area or natural opening in a body wall Hiatal hernia – stomach protrudes through diaphragm into chest cavity or esophagus – see heartburn, abd distention, chest pain, difficult swallowing – Tx – bland diet, small freq meals, staying upright after meals, surgery

Inguinal hernia

 Protrudes through lower abd wall  Sometimes can be reduced (pushed back into place)  Surgery

Pancreatitis

 Inflammation of pancreas where pancreatic enzymes begin to digest the pancreas itself  Pancreas becomes necrotic, inflamed, & edematous   Can lead to shock & hemorrhage if it extends into blood vessels Causes – excessive alcohol – Gallstones – idiopathic

Pancreatitis

 Sx – – Severe abd pain radiating to back – N & V – Diaphoresis – jaundice  Tx – Depends on cause – Pain control – Nutritional support – Surgery

Peritonitis

 Inflammation of peritoneal cavity  Usually occurs when intestine ruptures & allows contents to enter peritoneum  Common cause – ruptured appendix or gallbladder  Sx – abd pain, distension, N & V, fever  Tx – antibiotics, surgical repair

Ulcer

 Open sore on lining of digestive tract   May be gastric (stomach) or intestinal (Duodenal) H. Pylori – bacteria that burrows into stomach membranes and allow acids & digestive juices to create an ulcer  Sx – Burning pain, indigestion – Hematemesis – Melena

Ulcer

 TX – Antacids – Bland diet – Decreased stress – Avoid irritants (alcohol, fried foods, tobacco, caffeine) – With H.Pylori – give antibiotics & Pepto-Bismol – Severe - surgery

Ulcerative colitis

   Severe inflammation of colon accompanied by formation of ulcers & abscesses Causes – stress, food allergy, autoimmune Sx – bloody diarrhea – Pus, mucous – Weight loss – Weakness – Abd pain, anorexia – Anemia  Periods of remission & exacerbation

Ulcerative colitis

 Tx – Control inflammation – Reduce stress – Good nutrition – Avoid irritants – May need surgery & colostomy

Alactasia

 Lactose intolerance  Don’t produce enough lactase & so unabsorbed lactose ferments in intestines – gas, cramps, diarrhea  Tx – decrease dairy intake or take lactase supplements

Food poisoning

 Common, includes 300 illnesses transmitted by food (I.e. salmonella, listeria)  Sx – HA – Unrelenting diarrhea – N & V – Fever  Tx - antibiotics

Mumps

 Viral infection of parotid glands  Most common in 5 – 15 year olds  Parotids painfully swell  Can damage reproductive organs if older  Treat symptoms, no cure, runs its course

Phenylketonuria

 PKU  Inherited disease that can lead to mental retardation if untreated  1/8000 babies    Causes abn metabolism of proteins SX – irritability in infant, restless, eventually leads to convulsions TX – diet modification & routine blood work  All babies are tested

Pyloric stenosis

 Constricted pyloric sphincter  Doesn’t allow food to easily pass into small intestine  1/4000 infants  Sx – projectile vomiting, diarrhea, dehydration, weight loss  TX - surgery