Digestive Histologyand Physiology

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Digestive Histologyand Physiology

• SC.912.L.14.45
• SC.912.L.14.46

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Essential Question

• What are the organs of the digestive system?
• How is food digested?

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Digestive system..organs
pharynx
Oral cavity with salivary glands
esophagus
Liver and gall bladder
stomach
pancreas
Small intestine
Large intestine
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Activities occurring in the Digestive System
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Control of Digestive activity

• Chemical and pressure receptors
• Hormones
• Autonomic nervous system
• Central nervous system

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Salivary glands

• Salivary amylase secreted..digestion of starch
  and glycogen (polysaccharides)

parotid
submandibular
sublingual
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Esophagus
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Stomach

• Protein digestion begins here
• Secretions HCl and pepsinogen

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Control of HCl secretion

• Neural..parasympathetic
• Hormonal..gastrin
• Histamine

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Stomach Churning
3 ml. of chyme squirted out with each wave
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Small intestine

• Main function absorption.ileum main site
• Digestion of carbohydrates, fats and proteins
  occurs here

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Bile and pancreatic juice

• Bile
• Emulsifies fats
• Facilitate cholesterol and fat absorption
• Keep cholesterol dissolved in bile

• Pancreatic juice
• Proteases..digest protein
• Amylases..digest carbohydrates
• Lipases..digest fats
• Bicarbonate ions..neutralize acidity

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Segmentation and peristalsis
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Absorption in Small Intestine

• Water, electrolytes and nutrients absorbed
• Active and passive transport mechanisms used
• Absorption in simplest forms
• Glucose and amino acids enter blood stream
• Fat enters lymphatic system

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Large intestine

• Main function absorption of water, and
  elimination of feces
• Production of Vitamin K and B complex

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Day 2

• Divide your paper into 8 Frames. Draw a cartoon
  depicting the digestion of a hamburger.

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Day 3 - Continue

• Make a set of study cards with a partner. Put the
  organ one side and the functions on the other.
  Be sure you can recognize both sides.

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Day 4--- Fate of nutrients

• Where were they digested?
• How were they absorbed?
• Carbohydrates
• Proteins
• Lipids
• Water