Respiratory Organs Move Air
and Exchange Gases
LEARNING OBJECTIVES
1.
Identify
the structures of the respiratory
system.
2.
Explain
the functions of the respiratory system.
3.
Compare
what happens during breathing,
external respiration, and internal respiration.
he respiratory system consists of the nose,
pharynx (throat), larynx (voice box), trachea
(wind pipe), bronchi, bronchioles, and lungs
(Figure 13.1). The major purpose of the respi-
ratory system is gas exchange, which involves delivering
oxygen from the air to the body’s cells and tissues, removing
carbon dioxide from them, and expelling that carbon diox-
InSight
T h e r e s p ir a to r y s y s te m
Figure 13.1
The nose and pharynx make up the upper respiratory tract a., which prepares the air for
entry into the lower respiratory tract. The lower respiratory tract b. consists of the larynx,
trachea, bronchi, and bronchioles.
a.
Upper respiratory
tract
Nasal epithelium contains receptors for smell
(see Chapter 8)
Nasopharynx— Upper part of the pharynx
• Exchanges air with nasal cavity
• Receives mucus dust packages
and sends them to the mouth
• Equalizes air pressure in auditory
tube
Oropharynx—Middle part of the
pharynx that opens into the mouth
and nasopharynx. The palatine and
lingual tonsils located here carry out
immune reactions with pathogens in
incoming air.
Laryngopharynx—Lower part of the
pharynx that connects the esophagus
(food tube) and larynx.
Larynx
Thyroid cartilage
Cricoid cartilage
Thyroid gland
Nasal septum divides nasal
cavity into right and left sides.
Nasal conchae (KONG-ke)—Three
shelves of bone connect lined with
mucous membranes that warm,
humidify, and filter the incoming air.
Nostrils, or external nares—
Openings of the nose and upper
respiratory tract.
Which of the following properly orders the flow
of air from the environment to the alveolus?
a. Nasal cavity, larynx, pharynx, trachea, bron-
chus, bronchiole, alveolus
b. Nasal cavity, pharynx, larynx, trachea, bron-
chiole, bronchus, alveolus
\
c. Pharynx, nasal cavity, larynx, trachea, bron-
chus, bronchiole, alveolus
d. Nasal cavity, pharynx, larynx, trachea, bron-
chus, bronchiole, alveolus
e. Alveolus, bronchiole, bronchus, trachea,
larynx, pharynx, nasal cavity
_________________________________________________________
)
372 CHAPTER 13
The Respiratory System
previous page 407 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online next page 409 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online Home Toggle text on/off