BIO210
Respiratory System
Readings
6th
Edition
Pg. 827-830, 843-860
Figs. 23-1, 23-2, 2310, 23-12, 23-13, 2315, 23-16
7th Edition
Pg. 814-817, 829-847
Figs. 23-1, 23-2, 23-9,
23-11, 23-12, 23-14,
23-15
The functions of the respiratory system are:
1 Providing an extensive area for gas exchange between air
and circulating blood.
2 Moving air to and from the exchange surfaces of the
lungs.
3 Protecting respiratory surfaces from dehydration,
temperature changes, or other environmental variations
and defending the respiratory system and other tissues
from invasion by pathogens.
4 Producing sounds involved in speaking, singing, and
nonverbal communication.
5 Providing olfactory sensations to the central nervous
system from the olfactory epithelium in the superior
portions of the nasal cavity.
Organization of the respiratory system
Fig.
23-1
1
Respiratory Epithelium of Trachea
Fig.
23-2
Respiration
External Respiration
Internal Respiration
Fig.
23-12
Three main integrated steps involved in
respiration:
1 Pulmonary ventilation or breathing
2 Gas diffusion across the respiratory membrane and
across capillary walls
3 The transport of oxygen and carbon dioxide between
alveolar capillaries and capillary beds in other tissues.
2
Bronchi / Lung Lobules
Fig. 23-9
Bronchi / Lung Lobules
Fig. 23-9
Mechanisms of Pulmonary Ventilation
Fig. 23-14
3
Mechanisms of Pulmonary Ventilation
Fig. 23-14
Mechanisms of Pulmonary Ventilation
Fig. 23-14
Mechanisms of Pulmonary Ventilation
Fig. 23-14
4
Inhalation / Exhalation Pressure
Intrapulmonary or Intra-alveolar pressure - measured
inside the respiratory tract at the alveoli
Fig. 23-15
During inhalation, intrapulmonary
pressure is 759 mmHg (-1 mm Hg
below atmospheric pressure).
During exhalation, intrapulmonary
pressure is 761 mm Hg (+1 mm Hg
above atmospheric pressure).
Inhalation / Exhalation Pressure
Intrapleural pressure - measured in space between
parietal and visceral pleurae (ie. Pleural cavity)
Fig. 23-15
Intrapleural pressure remains below
atmospheric pressure throughout normal
cycles of inhalation and exhalation.
Inhalation / Exhalation Pressure
Fig. 23-15
Tidal volume is the volume of air
which you move into or out of your
lungs during a single respiratory cycle
5