The
Process of Gas Exchange
The following questions
will
help you to review the material from the lecture, as well as the text.
Make sure to take a look at the links to the images and the web sites
at
the end of the page. I have also included suggested reading material
in
case you would like to follow up on any of the aspects covered in this
section.
- Why is gas exchange a
necessity
(from a cellular perspective)?
- Briefly explain the
process of
cellular respiration (include the following processes: glycolysis,
the
Krebs cycle and the electron transport chain (ETC) in your answer)!
[feel
free to read this
summary from my Biology 10 class].
- Where does the carbon
dioxide
originate from? Why does it need to be removed from the organism?
What
will occur if the carbon dioxide accumulates within the organism?
- What is the importance
of accessing
oxygen? What exactly is it used for? What happens if there is no
oxygen
available?
- The term 'respiratory
system'
is typically used to refer to the system involved in providing gas
exchange
for the organism. What is the main physical process that is used for
the
actual movement of the two gases? Can the respiratory system handle
this
process alone in a larger organism?
- Discuss the different
strategies
of gas exchange in terms of internal and external surfaces. What
kind
of
attributes do these surfaces need to have? Is there a connection
with
the
type of habitat that the animal lives in? Explain!
- Why does the surface
area of the
exchange surface be large as well as moist?
- How does the amount of
available
oxygen vary between aquatic and terrestrial environments?
- How does the amount of
oxygen
vary between creeks/rivers versus stagnant water? Surface water
versus
water further down in the water column?
- What are the major types
of gas
exchange systems that have evolved in animals?
- Describe the use of
external surfaces
(skin/epithelium) in gas exchange. Describe the actual process of
gas
exchange.
Give several examples of animals that use this method. What is the
crucial
factor in terms of being able to use this type of gas exchange?
- Are animals that use
external
surfaces for gas exchange restricted to that method? Give examples
animals
that combine several types of gas exchange.
- Explain the concept of
gills in
animals. Is there a connection between gills and the circulatory
systems
in animals?
- Give examples of several
different
types of animals with gills?
- Make a drawing of fish
gills.
Label important structures.
- Describe the anatomy of
gills
in fishes (from macroscopic to microscopic levels). What are the
main
features
of gills in a fish?
- Explain the concept of
the counter-current
system as applied to the process of gas exchange in fish gills.
- Make a drawing of the tracheal
system in an insect. Label important structures.
- Describe the process of
gas exchange
in the tracheal system in the insects. How does the animal control
the
level of gas exchange?
- What is the function of
the air
sacs found within many insects?
- Is there a connection
between
gas exchange and desiccation in insects? Explain!
- Do insects depend on
their circulatory
system to transport oxygen and carbon dioxide within their bodies?
Explain!
- Describe the structure
of a book
lung as found in a spider (use a drawing).
- How does the gas
exchange process
occur in a book lung? Is the circulatory system involved in the
process?
- In what sense are diving
spiders
specialized in terms of their gas exchange?
- What are the basic
characteristics
of a lung?
- Where does gas exchange
occur
in a mammalian lung?
- How does a bird lung
differ from
a mammalian lung? Briefly explain the process of gas exchange as it
occurs
in a bird lung.
- Some mammals are amazing
divers
(e.g. the Weddell
Seal). How are these animals able to stay under water for more
than
an hour?
- Make a drawing of a
human lung
and label important parts in the upper as well as the lower
respiratory
tract. What are the functions of the different parts?
- How is it possible that
inhaled
air will be clean, humid and warm as it reaches the alveoli of the
lungs?
- What is the importance
of the
alveoli?
- Explain the process of
gas exchange
as it occurs between the alveoli and the capillaries in a human
lung.
- Why are the epithelia of
the capillaries
and the alveoli so thin?
- Describe the structure
of lung
tissue as viewed in a light microscope.
- Explain the process of
negative
pressure breathing.
- What is the difference
between
positive and negative pressure breathing?
- How does a lizard
breathe? Does
it strategy of breathing interfer with any other aspects of its
life?
- How does a crocodile
produce its
negative pressure in its breathing process?
- What factors control
breathing
in a human? Where is the breathing control center located?
- How is oxygen
transported with
in the blood? Describe the variety of proteins used in animals for
this
purpose!
- What is a heme group?
What is
its function?
- Hemoglobin is an amazing
protein
that has evolved to accommodate the process of gas exchange. Briefly
explain
some attributes of this protein that makes it such an excellent
candidate
for gas exchange in the human body.
- There are different
forms of hemoglobin
(e.g. fetal versus adult hemoglobin). Explain!
- Do all animals have
blood cells?
Explain!
- How is carbon dioxide
transported
in the circulatory system? In which chemical form is carbon dioxide
transported?
- Describe the process of
gas exchange
as it occurs between a developing human fetus and its mother.
Links:
Illustrations:
Self-test:
Recommended Reading:
