Health Occupations Digestive System
Feb 25, 2016
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 System1. Mouth
A. Food enters alimentary canal – INGESTIONB. Teeth – bite & chew food to physically break it downC. Tongue – tastes, chews (MASTICATION), & helps swallow (DEGLUTITION)D. Hard palate – anterior roof of mouthE. 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 chewingG. Process of mastication1. As food is chewed – mixes with saliva2. 3 salivary glands – secrete amylase to begin chemical breakdown of food (enzyme – protein that increases therate of chemical activity in body)a. Parotidb. Sublingualc. Submandibular
H. Begins the transformation of starch to sugarI. Bolus – portion of food, mixed with saliva, that is swallowed
2. Pharynx – 3 parts – nasopharnyx, oropharynx, laryngopharynxA. Food passes through oropharynx from mouth to esophagusB. Epiglottis closes so you don’t inhale food/drink
3. EsophagusA. Tube like structure carrying food from mouth to stomachB. Peristalsis – movement of food down esophagus with slow, wavelike movements
4. StomachA. Bolus mixes with HCL & enzymes pepsin & lipase to become CHYME (semifluid material)1. Pepsin – starts protein digestion2. Lipase – starts fat digestion3. HCL – kills bacteria, helps iron absorption, activates pepsin4. Rennin – in infants, helps milk digestion, not present in adults5. Direct absorption – alcohol, glucose,some drugs via stomach walls
6. Cardiac sphincter – valve preventing chyme from flowing backinto esophagus7. Pyloric sphincter – controls flowof chyme into intestines. Takes 1-4hours for stomach to empty into intestines
5. Small Intestine
A. Coiled section about 20 feet long, 1 inch in diameter
B. 3 sections1. Duodenum – 1st 9-10 inches where bile from gall bladder & liver & pancreatic juices enter through ducts2. Jejunum – 8 feet in length, middle section3. Ileum – final 12 feet, connects with large intestine at cecum
IleumA. Ileocecal valve – separates ileum & cecum,
prevents food from returning to ileumB. Digestion completed in small intestine, products are
absorbed into bloodstreamC. Intestinal juices produced by small intestine,
contains enzymes that break down sugars into simple forms (maltase, sucrase, lactase)
D. Also has pepsidases – protein digestionE. Steapsin – aids in fat digestionF. Bile – from liver & gall bladder to physically break
down fats
IleumG. Pancreatic enzymes – complete process of breaking
down food1. Pancreatic amylase – sugar2. Trypsin/chymotrypsin – proteins3. Lipase/steapsin – fats
H. 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
I. Only wastes, indigestibles, & water are left
6. Large Intestine
A. Final section, 5 feet in length, 2 inches in diameter
B. Functions1. Absorb water & other nutrients2. Stores indigestible materials before elimination3. Synthesizes & absorbs B vitamins & Vitamin K
by bacteria4. Transports wastes out
C. Divided into a series of connected sections
1. Cecum – 1st section, connected to ileum, contains appendix2. Colon – 4 partsa. Ascending – up right side of bodyto lower liverb. Transverse – across abd below liver & stomach, above sm intestinec. Descending – down left side of bodyd. Sigmoid – S shaped section, joins with rectum
e. Rectum – final 6 – 8 inches, stores wastes & indigestiblesf. Anal canal – narrow canal at
end, opening into anus where wastes
areexpelled through
7. Peritoneum
A. Flat serous membrane surrounding abdominal cavity
B. Lubricates & prevents friction between organs
C. 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 body1. Located under diaphragm in RUQ2. Secretes bile – emulsify fats & makes them water
soluble to be absorbed3. Stores sugar – glycogen, converts to glucose &
released to bloodstream when extra sugar is needed4. Stores iron & vitamins5. Produces heparin, fibrinogen, & prothrombin –
prevent clotting of blood6. Detoxifies substances like alcohol & pesticides7. Destroys bacteria taken into blood by intestine
B. Gallbladder
1. Small muscular sac located under liver, attached by connective tissue
2. Stores & concentrates bile (receives from liver)
3. Contracts when bile is needed to emulsify fats, bile goes through the common bile duct & into duodenum
C. Pancreas
1. Gland located behind stomach2. Produces pancreatic juices – contain
enzymes to digest food3. Pancreatic juices enter duodenum
through pancreatic duct4. Produces insulin which regulates
metabolism, burning of carbs to convert glucose to energy
Parotid glandEsophagusCardiac sphincterStomachPancreasTransverse colonDescending colonSigmoid colonRectumAnus
AppendixCecumIleum
Ascending colonDuodenum
Pyloric sphincterGall bladderLiverLarynxPharynx
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