Transcript CSI Bob… - wondersofscience

Digestive System Anatomy
Beginning the system
• Mouth
– Teeth
– Tongue
– Salivary glands
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•
Pharynx
Esophagus
Stomach
Small Intestine
– Liver and Pancreas
• Large intestine
The Mouth
• Teeth:
– The teeth help grind
up the food.
– Physical breakdown of
food.
– Function of various
teeth
• Incisors:
• Canines:
• Molars:
The Mouth
• Salivary Glands:
– Produce saliva
• Functions of saliva
– Humidifies the food
– Begins chemical
breakdown of starches
• Possible problems
– Tumors/ Cancer
– Infections
The Mouth
• Tongue:
– Deglutition
– Taste buds
– Prepares the bolus for
the esophagus
The Pharynx
• Part shared by both
the respiratory and
digestive systems
• Links the mouth to the
esophagus.
• What about choking?
Continuing down the Tract
• Mouth
• Pharynx
• Esophagus
– Cardiac Sphincter
• Stomach
• Small Intestine
– Liver and Pancreas
• Large intestine
The esophagus
• Where peristalsis
occurs:
– Rhythmic muscle
contractions that move
food through the
digestive tract.
– Basically squeezes the
food into the stomach
– Last about 9 minutes
The cardiac Sphincter
• Controls the amount of food let in
• Prevents the stomach acid from rising and
burning the tissues of the esophagus
• Basically the sphincter is a bouncer
• It is a type of valve
• Plays a major role in “burping”
The autopsy
• Mouth
• Esophagus
• Stomach
– Stomach
– Gastric Glands
– Pyloric Sphincter
• Liver and Pancreas
• Small Intestine
• Large intestine
The Stomach
• Mechanical and
Chemical
Transformations
• Mechanical
transformations
– It churns (mixes the
food with the stomach
acids and breakdown
the food)
The Gastric Glands
• Chemical Secretions of the stomach
– Pepsin
• Breakdown of proteins into shorter chains of amino
acids
– Stomach acid
• About 1- 4 on the pH scale
• Kills almost all the bacteria fund in your food
– Mucin
• Protective coating of the stomach
• What is an Ulcer
– An ulcer occurs when the gastric glands either
produce
• too much HCl or
• Too little mucin
• So basically an ulcer is created when your
stomach acid is burning through your stomach
lining
• Often occurs if someone is really really stressed
So far…
• The food is masticated, humidified and
turns into a bolus through deglutition.
• This bolus gets pushes down the
esophagus via peristalsis.
• It passes through the cardiac sphincter
and goes into the stomach.
• There it is churned and mixes with various
stomach acids and turns into a gucky
liquid called chyme.
Out of the stomach
• The pyloric sphinter controls the exit of the
chyme from the stomach.
• The stomach muscles will contract (every
5 minutes) releasing chyme into the small
intestine.