1. Respiratory System

2. exchange gases between blood (body) and the environment
Respiratory System
Function:
exchange gases between blood (body) and the environment
O2 in
CO2 out

3. Components:
  Airways
Lungs
Alveoli

4. Components of the Airway
Nares (nostrils)
Nasal cavity
clean, warm, moisten air
Pharynx (throat)
Larynx: contains vocal cords
Trachea: ciliated lining, cleans air
Bronchi enter lungs
Bronchioles (branches)

5. Components: Lungs: Alveoli: contain many alveoli (air sacs)
very large surface area
Alveoli:
site of gas exchange between air and blood
surrounded by capillaries
oxygen enters the blood and carbon dioxide enters the alveoli through diffusion.

7. How do we Breathe In? Diaphram contracts and moves down
Rib cage moves up and out
Size of the thoracic cavity increases
Pressure in the lungs decreases
Air rushes into the lungs from an area of high pressure to low pressure

8. How do we Breath Out? Diaphram relaxes and moves up
Rib cage moves down and in
Size of the thoracic cavity decreases
Pressure in the lungs increases
Air rushes out of the lungs from an area of high pressure to low pressure

9. What Controls Breathing Rate?
Brain senses carbon dioxide levels in the blood
If carbon dioxide levels increase, the brain signals the diaphragm to increase the rate of breathing.