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.
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