Digestive System (Gastrointestinal)

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Digestive System (Gastrointestinal)

• Functions of the Digestive system
• Intake and digestion of food
• Absorption of nutrients from
• Elimination of solid waste products
• Accessory Organs of Digestion
• Include the liver, ,
• and pancreas

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Anatomy

• Structures are divided into two sections
• Upper mouth, esophagus, stomach
• Lower small intestine, large
• intestine, rectum, anus
• Oral Cavity (mouth)
• Lips form opening to the mouth
• Hard palate portion of roof of mouth
• Soft palate portion of roof of mouth, closes
  off nasal passage during swallowing
• Uvula helps in producing sound and speech

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Upper GI tract Contd.

• Tongue strong and flexible, aids in speech and
  moves food during chewing and swallowing,
  contains which are also known as taste buds.
• Teeth 20 baby teeth, permanent teeth four
  kinds
• Incisors
• Canines
• Premolars (bicuspids)
• Molars

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Upper GI tract Contd.

• Parts of a tooth
• Crown the part of the tooth that is visible,
  covered with
• 2. Root holds the tooth securely in the dental
  arch
• Dentin makes up the of the tooth
• Gingiva (gums) surrounds teeth, covers the bone
  of the dental arches, forms the lining of cheeks
• Salivary Glands secretes saliva to moisten
  food, , cleanses the mouth

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Upper GI tract Contd.

• (also known as the throat)
• common passageway for food and air
• during swallowing, food is prevented from
  moving
• from the pharynx into the lungs by the
  epiglottis.
• Esophagus
• collapsible tube that leads from the
• pharynx to the
• the lower esophageal sphincter is a muscle that
  controls the flow between the esophagus and the
  stomach.

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Upper GI tract Contd.

• Stomach
• has 3 sections , body, and the
• the pyloric sphincter controls flow from
  stomach into the duodenum of the small
  intestine.

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Lower GI tract

• Small Intestine extends from pyloric sphincter
  to the large intestine in the small intestine is
  where 20 feet in length has three sections
• Duodenum , closest to the stomach
• Jejunum middle section, between duodenum and
  ileum
• Ileum , closest to the large intestine

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Lower GI tract Contd.

• Large Intestine waste products of digestion are
  processed in the large intestine and excreted
  through the anus has
• Cecum pouch that pouch that extends from the
  ileum to the beginning of the colon
• Ascending colon travels from cecum
• Transverse colon passes right to left toward
  the spleen
• Descending colon travels
• the left side of abdominal cavity
• Sigmoid colon joins descending
• colon with the rectum
• Rectum last division of the large intestine
• Anus is passed out of the body through the
  anus

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Accessory Organs of Digestion

• Liver (located in the right upper quadrant)
• removes excess from the bloodstream
• destroys old red blood cells
• removes poisons from blood
• makes some blood proteins
• secretes to break down fat
• Gallbladder
• stores and concentrates bile for later use
• Pancreas
• located posterior to the stomach, creates
  pancreatic juices to stomach acids and
  digestive enzymes to process protein,
  carbohydrates, and fat.

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Definitions
process by which complex foods are broken
down into nutrients that the body can
use Metabolism all of the processes involved
in the bodys use of these nutrients(building up
and breaking down of body cells) process
where digested nutrients are taken into the
circulatory system
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Definitions Contd
Mastication also known as chewing, breaks down
food into smaller pieces series of wavelike
contractions of smooth muscles in a single
direction. Chyme semi-fluid mass of partially
digested food that passes from stomach into small
intestine evacuation or emptying of the
large intestine
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Flow through the Digestive System
You will need to know the order of flow for food
moving through the digestive system on your next
test.
The Language of Medicine, 7th Edition Chabner,
Davi-Ellen Saunders, 2004
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ACTIVITY
How The Stomach Works