Respiratory System and Lung Cancer

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)


skin surface

simple lung


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.




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.

2 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.


Healthy lung

Cancerous lung

Facial cancer


Emphysema and chronic bronchitis - 2 major causes of chronic obstructive pulmonary disorder (COPD)

Emphysema Lung

Emphysema process

Comparison of emphysema alveoli and healthy alveoli.  X-section of lung with emphysema.


Asthma  Bronchioles   Allergens