Transcript digestive system - Livonia Public Schools

DIGESTIVE SYSTEM
THE MOUTH
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The initial place of digestion, teeth begin to
break down food into small pieces so the
digestive enzymes can break food up more
efficiently
Teeth
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Incisors
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Canines
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Secretes ptyalin
Breaks carbohydrates down into simple
sugars
Submandibular
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Brings food into contact with teeth
Helps to swallow food
Parotid
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Crush and grind food before swallowed
Tongue
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Tears dense food
Punctures food
Bicuspids and Molars
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Bite food with sharp edge
Bite into softer foods
Provides moisture and taste buds
Aids in the sensation of salty, sweet,
bitter, and sour
Sublingual
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Secretes ptyalin
Breaks carbohydrates down into simple
sugars
THE ESOPHAGUS
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Second step in digestion, where
food is moved from mouth to
stomach to be broken down into
simple form so body can absorb
and use it
– Bolus
• Mashed up food that is
swallowed
• The soft palate closes nasal
cavity and the epiglottis cover
the larynx
– Inner Layer
• Forms circles around
epiglottis
– Outer Layer
• Run longitudinally
• Approximately 10 inches
in length
THE STOMACH
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The place where the food is
broken up into the simplest form
Cardiac sphincter
– Opening into the stomach from
esophagus
• Dilates as the peristaltic
approaches
– One way gate into the stomach
• Closes after the entry of food so
nothing escapes
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3 layers
– Inner
• Thick and full of rugaes (folds)
• Capable of expanding to hold up
to a half gallon of food or liquid
– Circular
• Works with the oblique layer to
break down food into tiny particles
• The process will take longer if the
good is poorly chewed
– Oblique
• Works with the circular layer to
break down food into tiny particles
• The process will take longer if
food is poorly chewed
THE SMALL INTESTINE
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The narrow, winding, upper part of the
intestine where digestion is completed
and nutrients are absorbed by the
blood. It extends from the pylorus to
the cecum and consists of the
duodenum, the jejunum, and the
ileum.
Liver
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Bile
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Glycogen
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Aid in the digestion of fats
Secretes a pint a day
Gallbladder is the concentration and
storage area
Stored in liver
Form of glucose from a carbohydrate
Pancreas
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Secretion method
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Exocrine, through ducts
Endocrine, directly into blood stream
Secreted chemicals
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Pancreatic juice, reacts with all three
nutrients (carbohydrates, proteins,
glucose)
Insulin- allows sugar to enter the body’s
cells
THE LARGE INTESTINE
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The waste products, any indigestible material, and
the excess water is sent to the large intestine through
the ileocecal valve
The large intestine is 5 feet long, and 2 inches in
diameter
It is also known as the colon
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Cecum
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Rectum
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The collecting area for the remains of digestion. When
enough material is accumulated, sensors are activated and
the urge to defecate is felt. It’s 6 – 8 inches long
Anal canal
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Small pouch- like section of the colon, with the appendix
attached to it.
A narrow passageway about 1 inch long, extending for the
rectum to the anus.
The large intestine is divided into 4 sections
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Ascending section of colon- joins cecum at ileocecal
valve and continues upward.
Transverse section of colon- begins at the hepatic
flexure and extends in a loop across the abdominal
cavity to a point below the spleen, the splenic flexure.
Descending section of colon- begins at the splenic
flexure and extends downward along the left side of the
abdomen until it reaches the edge of the pelvic cavity
Sigmoid section of colon- S-shaped section of the long
intestine within the pelvic cavity. It extends from the left
iliac crest, over and back, to join the rectum
DIAGNOSTIC EXAMS
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Cholecystography
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Gastrointestinal Series (X-Rays)
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Exam of the lower rectum and anal canal through a 3 inch long protoscope
Sigmoidoscopy
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A stool sample is examined to look for blood. This diagnosis bleeding within the intestinal
tract
Proctoscopy
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Scanning of structures such as the spleen or liver, made visible by radioactive materials
Occult Blood Test
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Viewing of the esophagus, stomach and upper duodenum through a flexible scope that is
lighted by fiberoptics
Nuclear Medicine Study
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Exam to view the entire large intestine using a flexible fiberoptic scope
Gastroscopy
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Radiological studies of the GI tract
Colonoscopy
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X-Ray exam of the gallbladder following oral administration of a contrast medium
An exam to view the lower portion of the sigmoid and rectum through a 10-12 inch long
protoscope
Ultrasound
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Uses high frequency sound waves in order to view the liver, gallbladder, or pancreas
DISEASES OR DISORDERS
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Anorectal abscess and Fistula- localized infection due to a collection of
exudated in the soft tissue adjacent to the anus or rectum
Appendicitis- an acute inflammation of the appendix, usually caused by an
obstruction to the intestinal lumen
Cirrhosis- chronic disease of the liver, which causes destruction of liver
cells. This leads to impaired blood and lymph and interferes with the life
preserving functions of the liver
Colitis- inflammation of the colon
Colorectal Cancer- malignancy of the colon of rectum. The 3rd most
common cancer in men and women
Colostomy- artificial opening of the colon, allows fecal material to be
excreted from the body through the abdominal wall
Constipation- sluggish bowel action characterized by dry and infrequent
bowel movements
Chron’s- inflammation of any portion of the GI tract, most common terminal
ileum
Diarrhea- condition of repeated passage of unformed wastes
Diverticulosis- presence of bulging pouches in the wall of the GI tract where
the lining has been pushed into the surrounding muscle
Esophageal Varices- dilated, tortuous veins in the lower section of the
esophagus
Fissure of the anus- where there is a crack or tear in the lining of the anus
FOUR PHASES OF THE
DIGESTIVE PROCESS
• Ingestion: is the consumption of a substance by an
organism. In animals, it normally is accomplished by
taking in the substance through the mouth into the
gastrointestinal tract, such as through eating or drinking.
• Digestion: is the process by which the body breaks
down food into smaller components that can be
absorbed by the blood stream.
• Absorption: the process of absorbing or of being
absorbed
• Elimination: the act of discharging or excreting waste
products or foreign substances from the body, bodily
discharges including urine, feces, and vomit