Download The Respiratory System

The Respiratory System
Major Function of the Respiratory System:
To supply the body with O2 and dispose of CO2
Processes involved in respiration

Ventilation-movement of air into and out of the lungs

External respiration- gas exchange between the
blood (pulmonary capillaries) and the airsacs (alveoli)
in the lungs

Transport of respiratory gases- movement of O2
and CO2 between the lungs and the tissues

Internal respiration- gas exchange between the blood
(tissue capillaries) and tissue cells

* cellular respiration- utilization of O2 by cells for
energy (ATP) production via oxidative phosphorylation
Basic Anatomy of the Respiratory
System

Figure 22.1
Basic Anatomy of the Respiratory
System
 Upper
Respiratory Tract Organs
nasal cavity, pharynx, larynx
Accessory structures: oral cavity, sinuses
 Lower
Respiratory Tract Organs
trachea, bronchi, bronchioles, alveoli
Basic Anatomy of the Respiratory
System

Figure 22.1
Respiratory Mucosa
 mucous
membrane lining the respiratory
tract from the nasal cavity (and sinuses) to
the bronchioles
 epithelial layer is comprised predominantly
of ciliated, simple columnar epithelial cells,
with mucous-secreting goblet cells
interspersed

No cilia or goblet cells in smallest bronchioles
or alveoli
Respiratory Mucosa
 Conducting
Zone- structures from the
nasal cavity up to and including the
terminal bronchioles
 Respiratory
Zone- respiratory bronchioles
(with attached alveoli) through the alveolar
sacs
up to nasal cavity
Fig 22.7
Alveoli
 Microscopic
sacs where gas (O2/Co2)
exchange occurs; lined with simple
squamous epithelium
(called type I cells or Type I pneumocytes)
Alveoli
Figure 22.9c (not required)

Alveoli, together with the pulmonary capillary
endothelium→form the respiratory membrane
Alveoli



Microscopic sacs where gas (O2/Co2) exchange
occurs; lined with simple squamous epithelium
(called Type I cells or Type 1 pneumocytes)
Alveoli, together with the pulmonary capillary
endothelium→form the respiratory membrane
(also called the alveolar-capillary membrane). Site of
external respiration.
The thinness of the squamous alveolar cells and the
pulmonary capillary endothelial cells makes the
respiratory membrane very thin to allow efficient
O2/CO2 exchange
 Pleurae- serous membranes covering the
lungs; contain pleural fluid

protect and lubricate the lungs
 Pleurae- serous membranes covering the
lungs; contain pleural fluid

protect and lubricate the lungs
The two pleurae are separate sacs