Gas Exchange Review Unit#4 Lesson 1 Questions
1. What purpose is served by the respiratory
The main function of therespiratory system is gas exchange. This
refers to the process of Oxygen and Carbon Dioxide moving between the
lungs and blood . The respiratory system brings oxygen into the blood
so the blood can distribute to all of the body’s cells. It also turns oxygen
into nutrients and removes carbon dioxide from the body. The
respiratory system also regulates the body’s pH balance.
2. Why is the respiratory surface for terrestrial
organisms inside rather than outside the body?
Amphibians, frogs, and fish all use their skin as a respiratory surface to
obtain oxygen and eliminate carbon dioxide. Humans cannot diffuse
oxygen through their skin. They can only exchange about 1% of their
carbon dioxide through there skin. The same goes for terrestrial
animals; they are only able to exchange a very small amount of gases
through their skin. As a result, they must develop more efficient lungs in
order for their bodies to obtain an efficient amount of oxygen for bodily
functions. Thus, their respiratory systems are inside their bodies. Also,
respiration must take place in a moist environment. Aquatic animals live
in water, so they can exchange gas outside of their bodies seeing that a
moist environment is provided to them. The same cannot be said for
terrestrial animals since they live on land, and therefore since all of the
fluid is inside their bodies, respiration must take place inside.
3. How does the human respiratory system achieve
a large surface area?
The human respiratory system achieves a large surface area through
bronchioles and alveoli. Each bronchiole ends in a grape-like cluster of
tiny sacs called alveoli. If all of the alveoli in an average human lung
were spread out on a smooth surface, they cover bout 70 -90 meters
squared. As you can see, these structures greatly increase the surface
area of the lungs, which helps to maximize the volume of oxygen and
carbon dioxide that diffuses to and from the lungs.
4. Explain the process of breathing. 1. Inhalation beings with the intercostal muscles contracting. The
muscles associated with the ventral surface of the rib cage lif