Transcript The Digestive System

The Human Body Lesson
I honestly can’t tell if it’s a pie
eating contest or she’s trying out
for “The Walking Dead.”
• Digestion is the dismantling
of food into its chemical
components to be used for
fuel.
• The Alimentary Canal is
the 30ft long set of tubing
that food passes through.
• It begins at the mouth
where food enters, and
ends at the anus where left
over solid waste exits.
• The mouth is the first step of
digestion. Food is physically
broken down by the teeth.
• Saliva is produced by the
Salivary Glands. It chemically
breaks down food and
lubricates it.
• Saliva is produced more
when you smell or see food.
• The tongue and cheek then
roll the food into small balls
for easier swallowing.
Lots of Saliva
• The Esophagus is a short
length of tube between
the pharynx and the
stomach.
• It squeezes food down
to the stomach through a
process called peristalsis.
Making a peanut butter sandwich
in space
Peristalsis is what allows astronauts to swallow food to
their stomachs while pretending to be space bass
eating gummy worms.
• The stomach is a bag-like
organ that is closed at both
ends with valve-like sphincter
muscles.
• The stomach stores food for
about four hours before
heading into the small
intestine. It expands as it fills
with food.
• It breaks down food by
churning it around.
• The pyloric valve opens,
letting food enter the small
intestine.
Let's Journey to the Stomach!
A view from inside the stomach
• The acid found in your
stomach is called
Hydrochloric Acid.
• It is strong enough to burn
through skin but your
stomach is protected by a
layer of mucus.
• Your stomach also contains
enzymes, which help to
break down proteins.
Sometimes your stomach acid can eat a
hole through the wall of your stomach or
duodenum. This is called an ulcer.
This Cheeseburger is NOT in Paradise
• After leaving the stomach,
food passes through the
Duodenum, the first part of
the small intestine.
• The Small Intestine is the
longest part of the
alimentary canal. It is 20ft
long and this is where most
digestion takes place.
• Food is further broken
down by bile and
pancreatic juice.
Ironically, the small intestines of a pig looks
like sausage….which is made from pig.
• Bile is a digestive juice
that is produced in the
liver and stored in the
gall bladder. It helps to
break down fatty acids.
• The pancreas produces
enzymes that help break
down proteins,
carbohydrates, and fats.
• The Large Intestine is about 5
ft. long and is shorter but
much thicker than the small
intestine.
• Most digestion has happened
at this point but some salts
and water are absorbed
here.
• It holds waste in the rectum
until it exits through the anus.
• Chyme is the name for food
after it has been churned
and mixed with bile and
other digestive juices.