The primary function of the respiratory system is to provide oxygen to the body and remove carbon dioxide, a waste product of cellular respiration.

The heart is part of the circulatory system, not the respiratory system. The lungs, trachea, and diaphragm are all part of the respiratory system.

Respiration is the process by which oxygen is taken into the body and carbon dioxide is released. Diffusion, osmosis, and active transport are all processes by which molecules move across a concentration gradient.

The diaphragm is a muscle that contracts and expands the lungs, causing air to flow in and out.

The cilia in the respiratory system move mucus up the respiratory tract, helping to remove dust, pollen, and other particles from the lungs.

Surfactant is a substance that reduces the surface tension of the alveoli, making it easier for them to expand and contract.

Asthma is the most common respiratory disease, affecting over 25 million people in the United States.

Asthma is characterized by wheezing, coughing, shortness of breath, and chest tightness.

Smoking is the most common cause of COPD, accounting for over 80% of cases.

COPD is characterized by shortness of breath, wheezing, coughing, and fatigue.

Bacteria are the most common cause of pneumonia, accounting for over 50% of cases.

Pneumonia is characterized by fever, coughing, shortness of breath, and chest pain.

Bacteria are the most common cause of tuberculosis, specifically the bacterium Mycobacterium tuberculosis.

Tuberculosis is characterized by coughing, fever, weight loss, and night sweats.

Respiratory health can be improved by quitting smoking, avoiding air pollution, getting regular exercise, and eating a healthy diet.