,
,The Respiratory System
An Introduction to the Respiratory System
• does more than than move air in and out
• Gives the body energy through aerobic mechanisms (produced CO2)
• Our cells obtain oxygen and release CO2 when gases diffuse across the thin
respiratory exchange surfaces inside of the lungs
• lungs—a warm, moist, protected environment
• Diffusion to blood. Blood then circulates the oxygen and picked of the CO2
• Therefore, the cardiovascular system is the link between
• interstitial fluids and the exchange surfaces of the lungs.
23-1 The respiratory system, organized into an upper respiratory system and a
lower respiratory system,
Functions of the Respiratory System
• Providing an extensive surface area for gas exchange between air and
circulating blood.
• Moving air to and from the exchange surfaces of the lungs along the
respiratory passageways.
• Protecting respiratory surfaces from dehydration, temperature changes, and
pathogens.
• Producing sounds for speaking, singing, and other forms of communication.
• Detecting odors by olfactory receptors in the superior portions of the nasal
cavity.
Organization of the Respiratory System
• The respiratory system is organized in an anatomicalor functional perspective
, • we can divide the system into an
upper respiratory system and
A lower respiratory system
• upper respiratory system:
nose, nasal cavity, paranasal sinuses,
and pharynx
• The lower respiratory system: larynx (voice box), trachea (windpipe), bronchi
and bronchioles (air-conducting passageways), and alveoli (air-filled pockets
within the lungs).
functional perspective,
• respiratory tract - the passageways that carry air to and from the lung
exchange surfaces.
• The conducting portion of the respiratory tract begins at the entrance to the
nasal cavity and extends through the pharynx, larynx, trachea, bronchi, and
larger bronchioles.
• The passageways of the conducting portion of the upper respiratory system
filter, warm, and humidify inhaled air, protecting the more delicate surfaces of
the lower respiratory system.
• By the time air reaches the alveoli, most foreign particles and pathogens have
been removed, and the humidity and temperature are within acceptable limits.
due to the respiratory mucosa.
• The respiratory portion of the tract includes the smallest, thinnest respiratory
bronchioles and the associated alveoli, where all gas exchange between air
and blood takes place.
• the upper respiratory system contains the upper part of the conducting portion,
while the lower respiratory system includes the rest of the conducting portion
and all of the respiratory portion of the respiratory system.
