Digestive System. KEY TERMS Alimentary Canal Anus Colon Digestive System Duodenum Esophagus...
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Digestive System. KEY TERMS Alimentary Canal Anus Colon Digestive System Duodenum Esophagus Gallbladder Hard Palate Ileum Jejunum Large Intestine Liver
KEY TERMS Alimentary Canal Anus Colon Digestive System Duodenum
Esophagus Gallbladder Hard Palate Ileum Jejunum Large Intestine
Liver Mouth Pancreas Peristalsis Pharynx Rectum Salivary Glands
Small Intestine Soft Palate Stomach Teeth Vermiform Appendix
Villi
Slide 3
Digestive System The digestive system (gastrointestinal system)
is responsible for: 1.The physical and chemical breakdown of food
2.Absorption of nutrients 3.Elimination of wastes The digestive
system consists of: 1.Alimentary canal 2.Accessory organs
Slide 4
Alimentary Canal A long, muscular tube that begins at the mouth
and includes the: Mouth Pharynx Esophagus Stomach Small intestine
Large intestine Anus
Slide 5
Parts of Alimentary Canal Mouth receives the food Teeth help
with the mastication of food Tongue aids in chewing, swallowing,
and tasting of food Hard palate bony structure that is the roof of
your mouth, separates the mouth from the nasal cavities Soft palate
separates the mouth from the nasopharynx, includes the uvula which
helps to prevent food from entering the nasopharynx Salivary glands
produces salivary amylase which begins the chemical breakdown of
carbohydrates into sugars
Slide 6
Poly want a cracker?? A cracker is mostly a carbohydrate
(starch) but if you leave it in your mouth long enough it will
become a sugar. TRY IT!!!! Chew up an unsalted cracker but dont
swallow it! Keep the bolus (chewed up food) in your mouth for 1
minute After you notice the sweet taste you may swallow!
YUMMY!!!!
Slide 7
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Parts of Alimentary Canal (cont.) Pharynx (throat) carries both
food and air (air to the trachea and food to the esophagus) Bolus
(chewed food and saliva) enters the esophagus Epiglottis is closed
over the larynx to prevent food from entering the respiratory tract
Esophagus muscular tube behind the trachea that carries the bolus
to the stomach Like all parts of the alimentary canal, it relies on
peristalsis (rhythmic, wavelike, involuntary movement of muscles)
to move the food in a forward direction
Slide 9
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Parts of Alimentary Canal (cont.) Stomach Receives the food
from the esophagus Cardiac sphincter muscle b/n the esophagus and
stomach that closes after food enters Pyloric sphincter muscle b/n
the stomach and small intestine that keeps food in the stomach
until it is time to move on Food remains in the stomach for 2-4
hours Food is converted into chyme (semifluid material) by gastric
juices (hydrochloric acid and enzymes) Food is then ready to move
to the small intestine
Slide 11
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Parts of Alimentary Canal (cont.) Small intestine accepts chyme
from the stomach Coiled section that is approx 20 feet in length
and 1 inch in diameter Divided into 3 sections: Duodenum (first
9-10 inches) bile and pancreatic juices enter this section Jejunum
(8 ft in length) forms the middle section Ileum (final 12 ft)
connects with the large intestine at the cecum
Slide 13
Parts of Alimentary Canal (cont.) Small Intestine Process of
digestion is completed here Products of digestion are absorbed into
the bloodstream Bile from the liver and gallbladder physically
breaks down fat Wall of small intestine is lined with villi
(fingerlike projections) absorb the digested nutrients and carry
them to the liver Once food has completed its trek through the
small intestine, only wastes, indigestible materials, and excess
water remains
Slide 14
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Parts of Alimentary Canal (cont.) Large Intestine Last part of
the alimentary canal Approx 5 feet in length and 2 inches in
diameter Functions: Absorption of water and any remaining nutrients
Storage of waste before elimination Transportation of waste out of
the alimentary canal
Slide 16
Parts of Alimentary Canal (cont.) Large Intestine Divided into
a series of connected sections: Cecum - connected to the ileum of
the small intestine (contains the appendix) Colon Ascending colon
continues up the right side of the body Transverse colon extends
across the abdomen Descending colon extends down the left side of
the body Sigmoid colon S-shaped section that joins with the
rectum
Slide 17
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Parts of Alimentary Canal (cont.) Rectum final 6-8 inches of
the large intestine Storage area for indigestibles and wastes Has a
narrow canal called the anal canal which opens at the anus Anus
fecal material is expelled through this opening
Slide 19
Accessory Organs Liver The largest gland in the body Located
under the diaphragm in the upper right quadrant Secretes bile which
breaks down fats and makes them water soluble Stores sugar in the
form of glycogen, iron, and some vitamins Produces heparin
(prevents clotting in the blood) Detoxifies substances such as
alcohol and pesticides
Slide 20
Accessory Organs Gallbladder Small, muscular sac located under
the liver and attached to it by connective tissue Stores and
concentrates bile which is received from the liver Sends bile to
the duodenum when needed
Slide 21
Accessory Organs Pancreas Glandular organ located behind the
stomach Produces enzymes to digest food Produces insulin which
regulates metabolism (converting glucose into energy)
Slide 22
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Diseases and Abnormal Conditions Appendicitis Acute
inflammation of the appendix Resulting from an obstruction and
infection Symptoms abdominal pain that localizes in the LRQ, nausea
and vomiting, mild fever, and elevated WBC Rupture of the appendix
is a serious condition (infection spills into the peritoneal
cavity) Treatment - appendectomy
Slide 24
Diseases and Abnormal Conditions Cholecystitis Inflammation of
the gallbladder Symptoms occur after eating fatty foods and
include: indigestion, nausea and vomiting, pain that starts under
the rib cage and radiates to the right shoulder Treatment: low-fat
diet or a cholecystectomy Cirrhosis Chronic destruction of liver
cells which leads to scar tissue Some causes include hepatitis and
alcoholism Some common symptoms: liver enlargement, anemia,
jaundice, and hematemesis
Slide 25
Diseases and Abnormal Conditions Constipation Causes include a
diet low in fiber, dehydration, or extended laxative use Usually
self-corrected with diet, hydration, and exercise Diarrhea Causes
include infection, stress, and diet Treated by eliminating the
infection and modifying diet Hemorroids Painful dilated veins in
the rectum Causes include constipation, laxative abuse, or
pregnancy Treatment includes a high fiber diet, increased fluid
intake, or a hemorrhoidectomy
Slide 26
Diseases and Abnormal Conditions Diverticulitis Inflammation of
the diverticula (sacs that form in the intestine as the mucosal
lining pushes through the surrounding muscle) Occurs when fecal
material or bacteria become trapped in the diverticula Symptoms
include: abdominal pain, abdominal distention, low grade fever,
nausea and vomiting Treatment includes antibiotics, pain
medication, change in diet, or even surgery to remove the affected
section of the colon
Slide 27
Diseases and Abnormal Conditions Gastroenteritis Inflammation
of the mucous membrane that lines the stomach and intestinal tract
Causes include food poisoning, infection, and toxins Symptoms
include abdominal cramping, nausea, vomiting, fever, and diarrhea
Treatment includes rest, antibiotics, and increased fluid
intake