The Respiratory System

Respiratory Function

• The respiratory system facilitates the exchange of carbon dioxide and oxygen in the body.

• Pharynx: – Passageway for both

food and air in the back of the throat.

• Trachea: – Pipe that takes air

down into the lungs.

Larynx

• Also known as the voice box.

• Flaps of tissue that produce sound.

Bronchi

• Area where the trachea branches into two major portions that head into the lungs.

Bronchioles

• Small branches in the bronchi. They will continue to subdivide and get smaller as you move along the pathway.

Alveoli

• Air sacs at the end of the bronchioles.

• This is the area where oxygen and carbon dioxide are exchanged.

• Blood vessels run around these air sacs.

Breathing In

• 1. Diaphragm pushes down and the rib cage expands.

• 2. Thoracic cavity expands in size.

• 3. Air rushes in to fill that space.

Diaphragm’s Role in Breathing When the diaphragm contracts, the chest cavity enlarges, reducing the pressureinside. To equalize the pressure, air rushes into the lungs. When the diaphragm re-laxes, the elasticity of the lungs and chest wall pushes air out of the lungs.

Inhalation Exhalation

Chest contracts

Diaphragm relaxes

Chest expands

Sternum

Ribs

Lung

Diaphragm

Diaphragmcontracts

Breathing Out

• 1. Diaphragm pushes up and the rib cage pushes back.

• 2. The size the thoracic cavity shrinks.

• 3. The smaller overall space pushes the air out of the lungs.