Chapter 20 Digestive System

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Chapter 20Digestive System

• By Angie Lawson RN, BSN

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Overview

• Digestion
• Mechanical breakdown of food by physical means
• Chemical the chemical alteration of food
• Absorption movement of end products out of the
  digestive tract.

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Layers

• Mucosa innermost layer, mucous membrane
• Submucosa thick layer connective tissue
• Muscle Layer- smooth muscle layer
• This is where peristalsis occurs
• Serosa outermost layer

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Peritoneal Membranes

• Mesentery
• Mesocolon
• Greater Omentum resembles an apron draped over
  the abdominal organs
• Lesser Omentum

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Mouth

• Teeth
• Tongue
• Salivary Glands
• Other structures

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Teeth

• Mastication
• Deciduous teeth
• Permanent teeth
• Pulp

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Tongue

• Bolus ball like mass of food
• Frenulum anchors tongue to the floor of the
  mouth
• Sublingual to place under the tongue

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Salivary Glands

• Parotid
• Submandibular
• Sublingual
• Saliva watery fluid that contains mucus and the
  digestive enzyme Salivary amylase

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Other Structures

• Hard palate Soft Palate - make up the top of
  the mouth
• Uvula during swallowing it keeps food from
  moving upward into your nose

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Pharynx

• Deglutition
• Esophagus
• Epiglottis

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Esophagus

• Sphincters
• Pharyngoesophageal
• Gastroesophageal
• Lower Esophageal (LES) also known as cardiac
  sphincter
• Pyrosis heartburn, stomach contents refluxes
  into the esophagus

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Stomach

• Fundus
• Body
• Pylorus
• Greater
• lesser curvature
• Rugae allows the stomach to expand

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Stomach (cont)

• Chyme thick pastlike substance
• Vagus Nerve primary nerve in the digestive
  tract
• Mucus Cells
• Gastric Glands
• Gastric Juice

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Hiatal Hernia

• The stomach moves
• up through the
• diaphragm into the
• thoracic cavity

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Small Intestine

• Duodenum
• Jejunum
• Ileum
• Villi
• Chyle

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Large Intestine

• Cecum
• Colon
• Appendix

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Liver (Hepatic)

• Hepatic Portal
• System
• Liver Lobules
• Bile
• Biliary Tree

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Pancreas

• Main Pancreatic Duct
• Pancreatic Enzymes
• Acinar Cells
• Secretin

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Digestion Absorption

• Amylases digests polysaccharides
• Cellulose
• Proteases digests proteins
• Lipases digests fats
• Emulsification this process is carried out with
  the use of bile