Download Digestion Questions File

Digestion Questions
What is the purpose of teeth?
• The purpose of teeth is to tear and grind food
into smaller pieces that are able to be
swallowed. This also increases the surface
area of food, allowing enzymes to come in
close contact and begin the process of
chemical digestion.
How does the action of teeth aid in the action of
enzymes such as salivary amylase?
• When teeth crush food and increase the
available surfaces, this allows digestive juices,
such as salivary amylase, to contact more
surface of the food and increase the rate at
which digestion occurs.
What are three components of gastric
juice?
• Gastric juice is a secretion of the glands within
the stomach, the purpose of which is to
enable the breakdown of foods. To aid in this,
gastric juice contains hydrochloric acid,
proteases (such as pepsin), and mucus, which
helps to protect the lining of the stomach
from stomach acid.
Explain what chyme is.
• Chyme is the product of the first three organs
of the digestive system, the mouth,
esophagus, and stomach. All of the actions
that occur in these three organs help to form
chyme. Chyme, therefore is chewed food,
saliva (including salivary amylase), and gastric
juice (including HCl (aq), pepsin, and mucus).
Chyme, therefore, is a slippery slimy mass of
partially digested food.
Why is chyme especially important in
the absorption of nutrients?
• Absorption of nutrients occurs in the small
intestine, which has a narrow diameter and
many folds and finger-like projections. It is
important that food passing into this area be
in liquid form, so that it can flow into all the
crevices and take advantage of the huge
surface available for digestion. In solid form,
many fewer nutrients would be absorbed.
Where does absorption of nutrients
occur?
Absorption of nutrients
occurs in the lining of
the small intestine,
which is covered by
finger-like projections
called villi. Each villus is
also covered by microvilli.
What are the three sections of the
small intestine?
• The three sections of the small intestine are
the duodenum, the jejunum, and the ileum.
The duodenum is about 25 cm long, the
jejunum is about 2.5 m long, and the ileum is
about 3 m long.
What are the two major events that
occur in the large intestine?
• The two major events of the large intestine are
the production of Vitamin K and the absorption
of water.
• Beneficial bacteria in the large intestine produce
several helpful substances including Vitamin K,
B12, and some amino acids.
• The absorption of water from the large intestine
prevents the unnecessary loss of water from the
body, and also helps to solidify waste. Which
seems infinitely better than the alternative!
Why do we have an appendix?
• The appendix is attached to the large
intestine, but does not play a role in digestion.
It’s function is now believed to be to store the
beneficial bacteria that are present in the gut.
After an illness resulting in diarrhea, this
supply of helpful bacteria helps to re-establish
the proper conditions for digestion.
What is IBD?
• IBD refers to Inflammatory Bowel Disease (or
syndrome), and this is the general name for a
group of diseases in which the lining of the
intestine becomes inflamed, painful, and
possibly even non-functional. In some cases,
just the inner lining of the intestine is affected,
but in more serious cases, the entire thickness
of the intestinal wall may be damaged. The
disease can be very painful and debilitating.