Gas exchange in
animals (Fig. 30.1)
Fish (Fig. 30.2) and immature amphibians have gills. Fish have the most efficient
respiration with countercurrent flow. (Fig. 30.3)
lungs (Fig. 30.4)
Amphibians
skin
surface
simple
lung
Reptiles
Birds (Fig. 30.5)
crosscurrent
flow
air
sacs
The
Mammalian Respiratory System. The human respiratory system (Fig. 30.6)
lungs and bronchi (singular: bronchus)
thoracic
cavity
nasal cavity.
larynx
trachea
bronchial
tree and bronchioles
alveoli (singular:
alveolus)
pleural membrane
muscular
diaphragm
The mechanics of
breathing (Fig. 30.7)
Gas exchange (Fig. 30.9) (Movie)
hemoglobin
molecules (Fig. 30.8) of the red blood cells.
O2 Transport
CO2 Transport
Lung Cancer - Risks and Causes
Lung Cancer
in the United States (Fig. 30.10)
Mutations
to two of the most important tumor-suppressor genes and the proteins they produce, Rb and p53, are
implicated in development of cancer. (Fig. 9.14)
The Rb Protein
acts as a brake on cell division; mutations in the gene producing it cause cell
division to go out of control.
The p53
Protein, also called the "Guardian Angel" of the cell, inspects
the DNA to make sure it is ready for cell division.
Smoking Causes Lung
Cancer Movie
Lung
cancer kills more people than any other kind of cancer.
Carcinogens
in smoke cause mutations in lung cells.
Carbon
monoxide in smoke blocks the uptake of oxygen, making a person more likely to
become winded during exertions.
Lung
cancer rates in men and women. (Fig. 30.11)
Cancer cells grow at rapid rates and often metastasize to surrounding, or even distant,
tissue.
Exposure to some chemicals, asbestos, radiation can also cause lung cancer.
Emphysema
and chronic
bronchitis - 2 major causes of chronic obstructive pulmonary disorder
(COPD)
Comparison
of emphysema alveoli and healthy alveoli. X-section of lung with emphysema.