Download Extra study material for the Respiratory System

Concept Review: Respiratory
Respiratory

What is the function of the respiratory system?
Answer: The respiratory system brings oxygen to the body. It also helps eliminate waste gases. It works
closely with the circulatory system.

Why are the lungs important for the body?
Answer: The lungs are important because they draw in the air that we breathe. Air sacs fill with oxygen
and then pass the oxygen into the blood. The lungs also help expel waste gases.

What happens when we breathe?
Answer: When we breathe in, the diaphragm lowers and the air is drawn into the lungs through the mouth
or nose. The lungs expand to allow the air to enter, and tiny alveoli fill up. These alveoli then transfer their
oxygen to the blood, which brings the oxygen to all parts of the body. At the same time, the blood brings
waste materials, like carbon dioxide, from the body to the lungs, where it is released from our body when
the diaphragm presses upward and we exhale.
The Respiratory System
Essential Questions and Answers for Review Sheet

What is the function of the respiratory system?
Answer: The major function of the respiratory system is to transfer air into and out of the body so that gases
may be exchanged between the external environment and the circulatory system. This process facilitates
the moving of oxygen into the blood and the removal of carbon dioxide waste.

What happens when we breathe?
Answer: When we breathe, air is moved into and out of the lungs. Inhaling occurs when the diaphragm, a
strong muscle beneath the lungs, contracts and moves downward, causing the lungs to expand. At the
same time the rib muscles lift the ribs up and outward so that the lungs have more space. The expansion
of the lungs results in lower air pressure in the lungs than outside the body, forcing air to rush in. Air that
is inhaled into the lungs consists of mostly nitrogen with oxygen and small amounts of other gases,
including carbon dioxide. In the lungs, oxygen is transferred into the blood and carbon dioxide is removed
from the blood. Exhaling occurs when the diaphragm relaxes and moves upward, causing the lungs to
contact. This forces air out of the lungs. This air has a lower oxygen content and a higher carbon dioxide
content.

How do the parts of the respiratory system work together?
Answer: Air moves in through the nose or mouth and the lungs expand. The air travels down through
the pharynx and trachea and into the bronchial tubes, which branch into the bronchioles in the lungs. Finally
the air moves into tiny sacs called alveoli, which are tightly wrapped in capillaries. Some of the oxygen in
the air passes through the very thin walls of the alveoli and into the surrounding capillaries. At the same
time, carbon dioxide moves from the blood in the capillaries into the alveoli to be expelled.

How is breathing related to respiration and cellular respiration?
Answer: Respiration is the process by which oxygen and carbon dioxide are transported between the
external environment and cells in the body. Breathing is the process of taking air into the lungs and
expelling air from the lungs. The process by which cells in the body use oxygen to break down
carbohydrates to release energy is cellular respiration.

How is the respiratory system related to other body systems?
Answer: The respiratory system works very closely with other body systems. The diaphragm, which
contracts and relaxes to facilitate breathing, is also part of the muscular system. The ribs, part of
the skeletal system, protect the lungs. Most of the time breathing is an autonomic function that is controlled
by the brain, part of the nervous system. The lungs remove carbon dioxide waste from the body, one of the
functions of the excretory system. In the alveoli, oxygen and carbon dioxide are transferred between the
respiratory system and the blood, part of the circulatory system. The digestive system and the circulatory
system work together to provide nutrients to all of the body’s organs, including those of the respiratory
system.