00:01
So to wrap up our lecture
on the digestive system.
00:05
Recall that the digestive
system is responsible
for the digestion and absorption
of the nutrients that we ingest.
00:14
The GI tract of the
digestive system
begins at the oral cavity
and ends at the anus.
00:22
Also, we have accessory organs
not associated with the GI tract
that are necessary for digestion
and include the teeth, the
tongue, the salivary glands,
the liver, the pancreas,
and the gallbladder.
00:39
The mouth is responsible
for chemical digestion
of carbohydrates
and mechanical digestion
of our ingested food stuff.
00:49
The pharynx is responsible
for deglutition or swallowing
which is going to move
food to the esophagus.
00:58
The esophagus is responsible
for propulsion of food
toward the stomach by a
process known as peristalsis.
01:08
The stomach and its
acidic environment
begins chemical
digestion of proteins
and also involves mechanical
digestion of chyme.
01:21
The liver and the gallbladder
are going to work
to synthesize store
and release bile salts
that are needed for the
breakdown of lipids.
01:31
The pancreas is going
to synthesize enzymes
that are able to break down
all of the biomolecules
that enter into the
small intestines.
01:42
The small intestines is our
primary absorptive organ
of the digestive system.
01:49
It chemically digests substances
and absorbs them into the blood.
01:56
The large intestines contains
a diverse bacterial population
that completes some
chemical digestion as well.
02:05
The major function of the
large intestines, however,
is water absorption.
02:11
The rectum is going to
collect and store feces
until defecation occurs.
02:17
And defecation is going
to occur through the anus.
02:21
The digestion of
each biomolecule
is accomplished in
different portions
of the digestive system.
02:28
Carbohydrates are digested in
the mouth and small intestine,
proteins are digested in the
stomach and small intestine,
lipid digestion mostly occurs
in the small intestine,
and nucleic acid digestion also
occurs in the small intestine.
02:48
This concludes our lecture
on the digestive system.
02:51
Thank you for listening.