1. Respiratory System

2. Function Supply the blood with oxygen
For the blood to deliver oxygen to all parts of the body
Breathing
Inhale oxygen; exhale carbon dioxide

3. The Pathway Air enters the nostrils Passes through the nasopharynx
The oral pharynx
Through the epiglottis
Into the trachea
Into the right & left bronchi
Branches and rebranches
Into Bronchioles
Terminates in a cluster of
Alveoli

7. Alveoli ~300 million alveoli in two adult lungs
Provide surface area ~160 m2
~ equal to the singles area of a tennis court; 80 times the area of your skin

8. Breathing
Diaphragm
Divides the body cavity into the abdominal cavity & thoracic cavity
Pleural membranes
Lines inner surface of thoracic cavity & outer surface of the lungs

9. Pleural membrane Adheres to each other creating a natural elasticity
secretes a small amount of fluid that lubricates each surface
so that they slide past one another as the lungs expand and contract
If air is introduced between the membranes, lungs collapse

10. Breathing Inspiration (inhale) External intercostals muscles contact
Lifts ribs out and up
Diaphragm contracts
Draws downward
Expiration (exhale)
Processes are reversed & natural elasticity of lungs returns to normal volume
At rest, we breath times a minute; exchange ~500 ml of air

12. Breathing

13. Diseases of the Lungs Pneumonia Infection of the alveoli
Caused by many kinds of bacteria and viruses
Tissue fluids accumulate in the alveoli
Reduces surface area

14. Diseases of the Lungs Asthma
Constriction of the bronchi and bronchioles
Difficult to breathe in and out
Triggered by:
Airborne irritants
Chemical fumes, cigarette smoke
Airborne particles
allergies

15. Diseases of the Lungs Emphysema Alveoli break down
Reduces gas exchange area
Forces the heart to pump larger volumes of blood
Can lead to heart failure

16. Diseases of the Lungs Chronic Bronchitis
inflammation (or irritation) of the airways
Main cause is cigarette smoking

17. Diseases of the Lungs Lung Cancer Most common cancer and cancer deaths
Uncontrolled proliferation of cells
Most common types involve the epithelial cells lining the bronchi and bronchioles