1. The respiratory system exchanges oxygen and carbon dioxide.
picks up oxygen from inhaled air
expels carbon dioxide and water

2. Epiglottis - flap of skin that covers the trachea when swallowing
Path of air
Nose & mouth – air enters here. Nose is lined with hair and mucus membranes to help trap particles.
Epiglottis - flap of skin that covers the trachea when swallowing
Larynx – “voice box” where vocal cord are (2 ligaments)
nose
mouth
epiglottis
trachea
larynx

3. Trachea – cartilaginous “windpipe”
Path of air
Trachea – cartilaginous “windpipe”
Bronchi – tubes that lead to each lung
Bronchioles – branches off the bronchi
Alveoli – air sacs at the end of the bronchi where gas exchange with the blood occurs
trachea
lungs
bronchi
bronchi
bronchioles
lungs

4. Breathing involves the diaphragm and muscles of the rib cage.
Air flows from areas of high pressure to low pressure.
Air inhaled.
Muscles contract and
rib cage expands.
Diaphragm flattens
and moves downward.
Air exhaled.
Muscles and
rib cage relax.
Diaphragm relaxes
and rises.

5. The respiratory system moves gases into and out of the blood.
The lungs contain the bronchi, bronchioles, and alveoli.
Millions of alveoli give the lungs a huge surface area.
The alveoli absorb oxygen from the air you inhale.

6. Gas exchange occurs in the alveoli of the lungs.
Oxygen and carbon dioxide are carried by the blood to and from the alveoli.
oxygen diffuses from alveoli into capillary
oxygen binds to hemoglobin in red blood cells
carbon dioxide diffuses from capillary into alveoli
ALVEOLI
GAS EXCHANGES
alveolus
capillary
co2 o2
CO2 diffuses
into alveolus.
O2 diffuses
into blood.
capillaries

7. Gas exchange occurs in the alveoli of the lungs.
Breathing is regulated by the brain stem.
midbrain
pons
medulla oblongata
spinal chord

8. Smoking is the leading cause of lung diseases.

9. Smoking
Destroys alveoli.
Paralyzes the cilia that line your trachea and bronchi.
Causes genetic mutations leading to cancer.
Particles build up in your lungs and form tar.

10. Lung diseases reduce airflow and oxygen absorption.
Emphysema destroys alveoli.
Person has trouble exhaling enough air and looks “barrel-chested”

11. Asthma causes bronchioles to constrict due to muscle spasms
Attacks can be triggered by allergies, stress, exposure to smoke & chemicals, or exercise

12. Respiratory diseases interfere with gas exchange.
Cystic fibrosis genetic disease that produces sticky mucus
Clogs airways
Allows microorganisms to thrive in lungs