1. Respiratory System IN comes the OXYGEN, OUT goes the CARBON DIOXIDE!

2. Respiratory System: Function To bring about exchange of oxygen and carbon dioxide in the blood To bring about exchange of oxygen and carbon dioxide in the blood Oxygen fuels cellular respiration Oxygen fuels cellular respiration Carbon dioxide is a waste product from cellular respiration Carbon dioxide is a waste product from cellular respiration

3. Respiratory System: The Parts Nose and Mouth Nose and Mouth Bring in oxygen, expel carbon dioxide Bring in oxygen, expel carbon dioxide Why do you have nose hairs??? Why do you have nose hairs??? To clean incoming air of dirt and other harmful substances To clean incoming air of dirt and other harmful substances Pharynx: Pharynx: Passageway for air Passageway for air Larynx: Larynx: Located at end of pharynx Located at end of pharynx Contains the VOICE BOX Contains the VOICE BOX Trachea: Trachea: Air is cleaned by mucus and CILIA (tiny hairs) Air is cleaned by mucus and CILIA (tiny hairs)

4. Respiratory System: The Parts con’t.. Bronchus (pl. Bronchi) Bronchus (pl. Bronchi) Very large tubes that branch from trachea Very large tubes that branch from trachea Each leads to one LUNG Each leads to one LUNG Bronchioles: Bronchioles: Each bronchus branches into these smaller tubes Each bronchus branches into these smaller tubes Spread throughout each lung Spread throughout each lung

5. Respiratory System: The Parts con’t.. Alveoli : Alveoli : Tiny air sacs located at the end of bronchioles in the lungs Tiny air sacs located at the end of bronchioles in the lungs Site of gas exchange in the lungs Site of gas exchange in the lungs Surrounded by capillaries! Surrounded by capillaries! Oxygen diffuses into blood stream, Carbon dioxide diffuses out Oxygen diffuses into blood stream, Carbon dioxide diffuses out Look like bunches of grapes ! Look like bunches of grapes !

6. Gas exchange in alveoli

7. Respiratory System: Breathing Driven by air pressure created by chest cavity Driven by air pressure created by chest cavity Air moves from High to Low pressure Air moves from High to Low pressure Diaphragm: Diaphragm: Large, flat muscle located at the bottom of the lungs Large, flat muscle located at the bottom of the lungs Inhalation: Inhalation: Diaphragm FLATTENS AND CONTRACTS allowing air into the lungs Diaphragm FLATTENS AND CONTRACTS allowing air into the lungs Chest cavity EXPANDS Chest cavity EXPANDS Exhalation: Exhalation: Diaphragm RISES AND RELAXES forcing air out of lungs Diaphragm RISES AND RELAXES forcing air out of lungs Chest cavity COLLAPSES Chest cavity COLLAPSES Let’s see this in action! Let’s see this in action!