The Respiratory System

Respiration• Inhalation• Exhalation

The RS helps us to:• Transport air into the lungs.• Facilitate the diffusion of oxygen into the

blood stream.• Pick up waste carbon dioxide from the blood

and exhale it.

Phases of Respiration• External Respiration• Internal Respiration

Parts and FunctionsMouth, Nose, and Nasal Cavity• These three parts

warm and moisten the incoming air.

Pharynx• Contains the

windpipe/trachea and the food pipe or esophagus.

• Epiglottis prevents the food from entering the trachea.

Larynx• The voice box.• Helps protect the

trachea by producing strong cough reflex if any solid object passes the epiglottis.

Trachea

• Filter• Carries air from

throat into the lungs.

• It is covered with cilia.

Bronchi

• Carry air directly into the lungs.

Bronchioles

• Tertiary bronchi.• Carry air to the

Alveoli.

Alveoli• Permit the exchange

of gases, oxygen and carbon dioxide.

• 3 million alveoli

Diaphragm• It is the main muscle.