Transcript Digestive System

The Digestive System
Functions:
1) Breaks down food into
molecules the body can use.
2) Absorbs nutrients into the
blood
3) Eliminates wastes from the
body
Digestion
Two types of digestion:
1) Mechanical: physical
breaking apart of food
Ex: Chewing,
“Smushing”
Digestion
Two types of digestion:
2) Chemical: enzymes
break food into
molecules
Ex: saliva,
stomach acid
The Digestive Journey
1) Digestion begins at the mouth.
1) Teeth: mash and grind food
2) Salivary Glands: make saliva, which
breaks down food & makes it easier to
swallow
2) After food is swallowed, it travels through
the esophagus.
– Food is moved through this tube by muscles
contracting and squeezing. This process is
called peristalsis
– The esophagus delivers food to the stomach
3) The stomach is primarily composed of
muscles.
• Food is digested by mechanical and
chemical digestion until it turns into a
soupy substance called chyme.
4) Small Intestine
• The nutrients in chyme are absorbed into the
bloodstream through the walls of the small
intestine.
Absorption
• Digestive juices from the liver and
pancreas join the chyme.
• This turns the chyme into molecules small
enough to
get in
blood.
Absorption
• Villi: small, fingerlike projections, that
help small intestine absorb nutrients
5) Large Intestine
• Waste enters the large intestine as a
soupy material, but it is changed into a
semisolid waste called feces or stool.
• The rectum is the last part of the large
intestine. It stores feces until it can be
expelled.
• Feces pass through to the outside of your
body through an opening called the anus.
Other Digestive Organs
Liver: Makes bile (fluid that helps digest)
Other Digestive Organs
• Gall Bladder: stores and releases bile
Other Digestive Organs
• Pancreas: Produces enzymes to help
digest food
Other Digestive Organs
• *Food does not pass through the liver, gall
bladder, or pancreas.