Respiratory System Overview

Nasal Cavity

• Warms and moistens air so that it doesn’t damage the respiratory tract.

• Dust and debris is also removed by short hairs and mucous.

Pharynx

• “Back of the throat”• Shared by both the

respiratory tract and digestive tract

• Leads to the esophagus and larynx

Larynx

• “Voice box”• Contains the glottis (the opening to the larynx

and trachea)• Protected by a piece of cartilage called the

epiglottis, which closes during swallowing.• The opening is lined by elastic tendons called

vocal cords; small muscles change the tension in these tendons.

Larynx

Larynx

Trachea

• “Windpipe”• Tough, flexible tube that branches into the

right and left bronchi of each lung.• Carries air from the throat to the lungs• The walls of the trachea are supported by

tracheal cartilage (“C” shaped cartilage that prevents the trachea from collapsing)

Trachea

Bronchi

• Conducts air into lungs. • The right and left primary bronchi divide into

smaller passageways called secondary and tertiary bronchi. These divide into even smaller passageways called bronchioles.

• Tubes supported by cartilage.

Bronchi

Alveoli

• The end of the respiratory tract where gas exchange between blood and air takes place.

Diaphragm

• Skeletal muscle that divides the thoracic and abdominal cavities.

• Contraction of the diaphragm causes air to into the lungs (inhalation). Relaxation of diaphragm causes air to exit lungs (exhalation).

Diaphragm