Download Digestive System

Digestive System
Allied Health I
Alimentary Canal
 Alimentary Canal = Digestive tract or GI tract.
 30 ft tube from mouth to anus.
 Digestion = the process of changing complex
solid foods into simpler soluble forms which
can be absorbed by body cells.
Alimentary Canal
Functions of the Digestive System
 Physical breakdown of food.
 Chemical digestion of food into the end
products of fats, carbohydrates, & proteins.
 Allow absorption of nutrients into blood
capillaries of the small intestines.
 Eliminate waste products of digestion.
Lining of the digestive tract
 Does the digestive tract have an opening to
the outside?
 Then what type of membrane lines the entire
GI tract?
 Your right!!!!!!!!!
 A mucous membrane.
 What can a mucous membrane make?
 Your right again!!!!!!!!!
 Mucous.
Lining of the Abdominal Cavity
 The membrane, or you
could think of it as a
balloon, that lines the
abdominal cavity is the
Peritoneum or
Peritoneal Membrane.
 It is like a balloon that
surrounds all of your
abdominal organs.
 This membrane is a
Serous Membrane.
Lets begin our Journey!
 The Mouth = food enters the
digestive system here.
 The inside of the mouth is
covered with a mucous
membrane called the oral
mucosa.
 The roof of the mouth is the
hard palate.
 Uvula = prevents food from
going up into the nasal cavity
when you swallow.
Accessories of the mouth
 Teeth aid in Mastication
(chewing).
 Gingiva = gums, help
support & protect teeth.
 Deciduous teeth = baby
teeth = 20
 Adult teeth = 32
Accessories of the mouth
 Salivary glands =
produce/secrete saliva.
 Three pairs of salivary
glands, parotid is the
largest. Parotid becomes
inflamed during mumps.
 Ptyalin = enzyme in
saliva that converts
starches to simple sugars.
Accessories of the mouth
 Tongue
 Attached to floor of
mouth.
 Made of skeletal
muscle.
 Aids in chewing,
swallowing, & tasting.
 Taste buds on surface
Esophagus
 ~ 10 inch long
muscular tube.
 Connects pharynx &
stomach.
 There is a circular
muscle called the
cardiac sphincter
where the esophagus
meets the stomach.
Stomach
 Upper mid/left abdominal cavity.
 Lined with a mucous membrane.
 Special cells make acid to help digest food.
 Mucous is important in protecting stomach
lining from acid.
 Rugae – stomach is in folds when it is not full
of food.
 Stomach also has a muscle layer so that it
can contract, churn food, & push food out.
Stomach
Stomach
 At the bottom of the
stomach is the
Pyloric Sphincter.
 The pyloric sphincter
regulates the entrance
of food from the
stomach into the
duodenum (first part of
small intestine).
Small Intestine
 Duodenum – first segment, curves around
pancreas, ~ 12 inches long.
 Duodenum is where digestive enzymes from
the pancreas are added to food.
 Duodenum is also where bile from the
gallbladder is added to food.
 Jejunum – middle segment, ~ 8 ft long.
 Ileum – final segment, ~ 10 to 12 ft long.
Small Intestine
Small Intestine
 Absorption – in small intestine, nutrients pass into
bloodstream & on to body cells, food that can’t be
digested moves on to the large intestine.
Large Intestines
 ~ 2 inches in diameter.
 Also called the colon.
 Cecum = blind passage.
 The cecum is the first part of the large
intestine.
 The cecum is in your ® lower quadrant(RLQ).
 The appendix is a finger-like projection that
hangs off the cecum.
Cecum & Appendix
Large Intestine
 Next, the ascending colon ascends up the ®
side of the abdomen.
 The transverse colon travels from R to L.
 The descending colon moves from L upper to
L lower quadrant.
 Next is the Sigmoid colon which has a curvy
shape and connects to the Rectum.
 The Rectum is the last portion of the large
intestine & is where feces awaits defecation.
 Anus – sphincter, external opening.
Large Intestine / Colon
Accessory Organs
 Pancreas
 Exocrine function is
to produce & secrete
digestive enzymes.
 Also has an
endocrine function.
 Feather shaped,
located behind the
stomach.
Accessory Organs
 Liver
 Largest Organ in the body.
 Located below the diaphragm, ↑ ® quadrant.
 Connected to gallbladder & small intestine by ducts.
 Functions include:
 Produce & store glucose in the form of Glycogen.
 Detoxify alcohol, & drugs.
 Manufacture blood proteins.
 Manufacture bile.
 Store Vitamins A, D, & B complex.
Liver
Accessory Organs
 Gallbladder
 Small greenish organ,
inferior surface of liver.
 Stores & concentrates bile
until needed.
 When fatty foods are
digested, bile is released
by the gallbladder to help
break down the fat.
Digestion (in the mouth)
 Food is chewed & saliva is added to create a
soft, pliable ball called a bolus.
 Salivary glands are under Nervous control,
just thinking of food makes your mouth water.
 The bolus slides down the pharynx &
esophagus.
 Peristalsis = wavelike motion that moves
food along the digestive tract.
Digestion (in the stomach)
 Bolus enters after passing by the cardiac
sphincter.
 Gastric digestive juices are released & mix
with bolus as the stomach churns.
 The mixture is now called Chyme.
 Small amount of chyme enter duodenum at a
time – controlled by the pyloric sphincter.
 Takes ~ 2 to 4 hours for stomach to empty.
Digestion (in small intestine)
 Duodenum - addition of digestive enzymes
from pancreas & bile from the
liver/gallbladder.
 Small intestine = where digestion is
completed & absorption occurs.
Digestion (in large intestine)
 Regulation of H²O, vessels of large intestine
absorb water from undigested food that is
moving along.
 Bacteria (normal flora) acts on undigested
food.
 Bacteria form moderate amounts of B
complex, vitamin K, and gas.
 Flatulence - ~14 times a day to get out the 13 pints of gas that is produced.
Digestion (in large intestine)
 Feces – undigested semi-solid mixture
consisting of bacteria, waste products,
mucous, & cellulose.
 Defecation – reflex is triggered, colon & rectal
muscles contract, while internal sphincter
relaxes – the external anal sphincter is under
conscious control.
Disorders of the Digestive System
 Heartburn = Acid Reflux = GERD
 Stomach acid/chyme moves in opposite direction,
moves back up through cardiac sphincter & burns the
lining of the esophagus.
 Symptoms = burning sensation.
 Treatment =
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Avoid chocolate, peppermint, coffee, citrus, fried/fatty
foods, & tomato products.
Stop smoking.
Take antacids.
Don’t lay down 2-3 hrs after eating.
GERD
GERD
Inside the esophagus with GERD
EGD
 http://www.nlm.nih.gov/medlineplus/surgeryvi
deos.html
Disorders
 Ulcers
 Sore or lesion that forms in the lining of the stomach
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or GI tract.
Gastric ulcer in the stomach, duodenal ulcers in the
duodenum.
Primary cause = H. pylori (bacteria)
Contributing factors = smoking, alcohol, stress,
certain drugs.
Symptoms = burning pain in abd between meals &
early morning, may be relieved by eating or taking an
antacid.
Diagnosis = Esophagogastroduodenoscopy (EGD)
Ulcers
H. Pylori
Gastroenteritis
 Inflammation of the mucous membrane lining
the stomach & intestines.
 Common cause = virus, could also be caused
by food poisoning.
 Symptoms = diarrhea & vomiting.
 Complication = dehydration.
Diarrhea
 Loose, watery, frequent bowel movements
when feces passes through colon too rapidly.
 Causes = infection, poor diet, nervousness,
toxic substances, or food irritants.
Constipation
 When defecation is delayed, feces becomes
dry & hard.
 Causes = poor diet, not taking time to
defecate, immobility.
 Treatment = diet of cereals, fruits, vegetables.
Also drink plenty of liquids, & exercise.
Appendicitis
 When appendix
becomes infected &
inflamed (red & swollen).
 If it ruptures, bacteria
can spread to peritoneal
cavity (abd cavity).
 Symptoms = RLQ pain,
fever, N & V.
 Treatment =
appendectomy.
Appendectomy
IBS
 Irritable bowel syndrome.
 Symptoms = Abd cramping, Diarrhea,
Constipation.
 Diagnosis = When all other GI problems have
been ruled out, they label you as having IBS.
 Treatment = Good diet,  fiber,  diary.
Hepatitis A
 Inflammation of the Liver.
 Caused by virus.
 Spread through
contaminated food &
water.
Hepatitis B
 Inflammation of the Liver.
 Caused by a virus.
 Spread through contact with blood or body
fluids.
 Health Care Workers at risk should be
vaccinated.
 Prevention = Standard Precautions (PPE)
Hepatitis B
Cirrhosis
 Chronic, progressive
disease of the liver.
 Normal tissue replaced
by fibrous connective
tissue.
 75% caused by excessive
alcohol consumption.
Jaundice
 Yellow color of the skin.
 Caused by damage to the liver.
Cholecystitis
 Inflammation of the gallbladder.
 Can also have Cholelithiasis (gallstones).
 Small stones may pass but large stones may
becomes lodged in the ducts running from the
gallbladder to the duodenum.
 Symptoms = stabbing pain through front to
back between shoulder blades, N & V.
 Treatment = Cholecystectomy
Cholelithiasis