1. Respiration
The respiratory system brings air rich in oxygen into the body
and gets rid of air rich in carbon dioxide.

2. nasal cavity nostril mouth pharynx larynx trachea lung bronchus12
nostril
mouth
pharynx
larynx
trachea
lung
bronchus
bronchus
bronchiole
alveoli
diaphragm

3. Compare inhaled and exhaled air. What is the trend?
GAS N2 O2 Ar
CO2
INHALED
EXHALED
78%
21%
~1%
0.04%
78%
16%
~1% 5%

4. Breathing (Ventilation)
Inhalation
The diaphragm and intercostal muscles contract.
The chest cavity enlarges.
The pressure in the lungs decreases.
Air rushes into the lungs.

5. Breathing (Ventilation)
Exhalation
The diaphragm and intercostal muscles relax.
The chest cavity decreases in size.
The pressure in the lungs increases.
Air rushes out of the lungs.

7. What pathway does air follow as you inhale?
nasal cavity or mouth
pharynx (throat)
larynx and vocal cords
trachea
bronchi
bronchioles
alveoli

9. What pathway does air follow as you exhale?
nasal cavity or mouth
pharynx (throat)
larynx and vocal cords
trachea
bronchi
bronchioles
alveoli

10. Air processing
Blood vessels in your nasal cavity and respiratory passages warm the air.
Mucous in your nasal cavity and respiratory passages
moistens the air
and also traps dust and germs.
Nose hairs increase the surface area of this mucous
Cilia in your respiratory passages sweep mucous up out of lungs.

11. Asthma

12. Gas Exchange
In the alveoli, oxygen diffuses into blood vessels and carbon dioxide diffuses out of the blood vessels.

13. Circulation
The circulatory system distributes nutrients and oxygen to all of the body’s cells,
removes waste from cells,
and regulates the body’s temperature.

14. Blood Blood is composed of cells and plasma.
Plasma is the liquid component of blood in which blood cells are suspended.

15. Red blood cells carry oxygen from the lungs to the body’s cells,
and carbon dioxide from the body’s cells to the lungs.

16. White blood cells fight infections.

17. Platelets allow the blood to clot when blood vessels are broken.

18. Blood Vessels Arteries carry blood away from the heart.
Veins carry blood to the heart.

19. Capillaries are the smallest blood vessels
Capillaries are the smallest blood vessels. Their walls are only one cell thick.
Capillaries supply oxygen and nutrients to every cell in the body,
and remove carbon dioxide and wastes.

20. The Heart The heart has 4 chambers:
The right chambers receive deoxygenated blood from the body and pump it to the lungs.
The left chambers receive oxygenated blood from the lungs and pump it to the body.