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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
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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
Coiled section about 20 feet long, 1 inch in
diameter
B. 3 sections
1. Duodenum – 1st 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
A.
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.
Pancreatic enzymes – complete process of
breaking down food
1. Pancreatic amylase – sugar
2. Trypsin/chymotrypsin – proteins
3. 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
Final section, 5 feet in length, 2 inches in
diameter
B. Functions
A.
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 – 1st 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
Flat serous membrane surrounding
abdominal cavity
B. Lubricates & prevents friction between
organs
C. Mesentary – fan-shaped projection of
peritoneum that contains blood vessels &
nerves
A.
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
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
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 –
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Hepatitis
Bile duct disease
Chemical toxins
Malnutrition associated with alcoholism
Symptoms
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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 –
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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
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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
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Abd pain, N & V
Irregular BM
Flatus, constipation, diarrhea
Abd distension
Low grade fever
Diverticulitis
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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
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Tx
– Rest, fluids
– Antibiotics, IV
– Meds to slow peristalsis
Hemorrhoids

Painful, dilated or varicose veins of rectum or
anus
 Causes –
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Straining to defecate
Constipation
Pressure during pregnancy
Insufficient fluids
Laxative abuse
Prolonged sitting or standing
Hemorrhoids
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Sx
– Pain
– Itching
– bleeding

Tx
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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
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Sx –
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Severe abd pain radiating to back
N&V
Diaphoresis
jaundice
Tx
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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
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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
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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
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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
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Phenylketonuria
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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
