Respiratory System IN comes the OXYGEN OUT goes

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

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

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

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

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

Gas exchange in alveoli

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