Respiration
• Pulmonary ventilation (breathing):
movement of air into and out
of the lungs
• External respiration: O2 and CO2
exchange between the lungs
and the blood
• Transport: O2 and CO2
in the blood
• Internal respiration: O2 and CO2
exchange between systemic blood
vessels and tissues
Respiratory
system
Circulatory
system
Nasal cavity
Nostril
Oral cavity
Pharynx
Larynx
Trachea
Carina of
trachea
Right main
(primary)
bronchus
Right lung
Left main
(primary)
bronchus
Left lung
Diaphragm
Figure 22.1
Frontal bone
Nasal bone
Septal cartilage
Maxillary bone
(frontal process)
Lateral process of
septal cartilage
Minor alar cartilages
Dense fibrous
connective tissue
Major alar
cartilages
(b) External skeletal framework
Figure 22.2b
Cribriform plate
of ethmoid bone
Sphenoid sinus
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Internal nare
Nasopharynx
Opening of
pharyngotympanic
tube
Uvula
Nostril (external nare)
Oropharynx
Hard palate
Soft palate
Tongue
Laryngopharynx
Esophagus
Trachea
(c) Illustration
Hyoid bone
Larynx
Epiglottis
Vestibular fold (false vocal cords)
Thyroid cartilage
Vocal fold (at the glottis)
Thyroid gland
Figure 22.3c
Epiglottis
Body of hyoid bone
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
Tracheal cartilages
(a) Anterior superficial view
Figure 22.4a
Epiglottis
Body of hyoid bone
Glottis
Vestibular fold
(false vocal cord)
Thyroid cartilage
Vocal fold
(true vocal cord)
Tracheal cartilages
(b) Sagittal view; anterior surface to the right
Figure 22.4b
Mucosa
• Pseudostratified
ciliated columnar
epithelium
• Lamina propria
(connective tissue)
Submucosa
Seromucous gland
in submucosa
Hyaline cartilage
(b) Photomicrograph of the tracheal wall (320x)
Figure 22.6b
Tracheal Cross Section
Hilus/hilum of left lung
(triangular depression on
posterior surface)
Trachea
Apex
Superior lobe
of left lung
Left main
(primary)
bronchus
Lobar
(secondary)
bronchus
Segmental
(tertiary)
bronchus
Superior lobe
of right lung
Middle lobe
of right lung
Inferior lobe
of right lung
Base
Cardiac notch
Inferior lobe
of left lung
Figure 22.7
Thoracic Cross Section Showing Pleura
Alveoli
Alveolar duct
Respiratory
bronchioles
Terminal
bronchiole
Alveolar duct
Alveolar
sac
(a)
Figure 22.8a
Microscopic View of Lung Tissue
Red blood
cell
Nucleus of type I
(squamous
epithelial) cell
Alveolar pores
Capillary
O2
Capillary
CO2
Alveolus
Alveolus
Type I cell
of alveolar wall
Macrophage
Endothelial cell nucleus
Alveolar
epithelium
Fused basement
membranes of the
Respiratory alveolar epithelium
membrane and the capillary
Red blood cell
endothelium
Alveoli (gas-filled in capillary
Type II (surfactantCapillary
air spaces)
secreting) cell
endothelium
(c) Detailed anatomy of the respiratory membrane
Terminal bronchiole
Respiratory bronchiole
Smooth
muscle
Elastic
fibers
Alveolus
Capillaries
(a) Diagrammatic view of capillary-alveoli relationships
Figure 22.9a
Respiratory Volumes
• Used to assess a person’s respiratory
status
– Tidal volume (TV)
– Inspiratory reserve volume (IRV)
– Expiratory reserve volume (ERV)
– Residual volume (RV)
Using a Wet Spirometer
Respiratory Volumes and Capacities
•
•
Factors Affecting Respiratory Capacity: Size, Gender, Age, Condition
Normal breathing moves
about 500 ml of air with
each breath (tidal volume
[TV])
•
Inspiratory reserve
volume (IRV)
–
–
•
Amount of air that can be
taken in forcibly over the
tidal volume
Usually 2100-3200 ml
Expiratory reserve
volume (ERV)
–
–
Amount of air that can be
forcibly exhaled
Approximately 1200 ml
Respiratory Volumes and Capacities
•
Residual volume
–
–
•
Air remaining in lung after expiration
About 1200 ml
Functional volume
–
–
Air that actually reaches the
respiratory zone
Usually about 350 ml
•
Vital capacity
–
–
–
The total amount of exchangeable air
Vital capacity = TV + IRV + ERV
Dead space volume ~ 150 ml
• Air that remains in conducting zone and
never reaches alveoli
Inspiratory
reserve volume
3100 ml
Tidal volume 500 ml
Expiratory
reserve volume
1200 ml
Residual volume
1200 ml
Inspiratory
capacity
3600 ml
Vital
capacity
4800 ml
Total lung
capacity
6000 ml
Functional
residual
capacity
2400 ml
(a) Spirographic record for a male
Figure 22.16a