THE RESPIRATORY SYSTEM

• provides oxygen to the cells and

removes carbon

dioxide from the body.

• works closely with circulatory system.

• made of following parts:

–nasal cavity

–mouth

–trachea

–bronchi

–lungs

–diaphragm

–Nelson Science

Gas Exchange

• travels through the trachea (windpipe) to the lungs.

• trachea has cells that have hairlike projections called cilia.

• Cilia filter out and remove foreign materials (such as dust)

• oxygen enters the bloodstream in the lungs by diffusion and carbon

dioxide leaves

• gas exchange takes place in the alveoli, which are surrounded by

capillary networks containing blood.

Breathing

• Air is drawn into the lungs by

inhaling and is then pushed

out by exhaling.

• Breathing is controlled

involuntarily.

• muscles move ribs and lower

diaphragm making air flow

into lungs (inhalation)

• opposite happens for

exhalation

Diseases

• constantly exposed to substances in the

air, so it can be affected by many different

diseases.

• Tuberculosis (TB) - bacteria that are

breathed into the lungs, where they grow

• Tobacco smoke - contains carcinogens

This chest X-ray shows evidence of TB in the upper part of the lung on the right.