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Respiratory System

LungsThe respiratory system starts at the mouth and nose and ends with the alveoli in our lungs. When we breathe, the air enters our mouth or nose, passes through to the pharynx in the throat, down the larynx (voice box) and the trachea (windpipe) to the lungs. The trachea splits near the bottom into the primary bronchi, which enter the lungs. Each bronchus then divides into secondary bronchi, which divide more into bronchioles, which keep dividing into alveolar ducts, which finally contain the alveoli.

The alveoli are very small air sacs. Blood is brought to the alveoli from the heart by the pulmonary artery. (Read about "Vascular System") While in the capillaries surrounding the alveoli, the blood gives off carbon dioxide through the capillary wall into the alveoli and takes up oxygen from the air in the alveoli. The oxygenated blood is then carried away by the pulmonary veins, and brought back to the heart. From there, the blood is sent out to the rest of the body.

There are many medical conditions that can affect the respiratory system and how we breathe - from the common cold, all the way to lung cancer. Some are caused by microorganisms (Read about "Microorganisms") including common viral infections such as the flu or respiratory syncytial virus, which is known as RSV. Others are the result of chronic conditions such as asthma, allergies and cystic fibrosis. By following the links below you can learn more about many of these conditions.

Acute bronchitis: see Acute Bronchitis

Acute respiratory distress syndrome: see Acute Respiratory Distress Syndrome (ARDS)

Acute sinusitis: see Sinusitis & Rhinitis

Allergic rhinitis: see Sinusitis & Rhinitis

Allergies: see Allergies

Allergies, animal dander: see Animal Dander

Allergies, dust: see Dust Allergies

Allergies, mold: see Mold Allergies

Allergies, pollen: see Pollen Allergies

Animal dander: see Animal Dander

Apnea, sleep: see Sleep

Asbestosis: see Occupational Respiratory Diseases

Asthma: see Asthma

Black lung: see Occupational Respiratory Diseases

Bronchiolitis: see Bronchiolitis

Bronchitis, acute: see Acute Bronchitis

Bronchitis, chronic: see Chronic Obstructive Pulmonary Disease

Bronchopulmonary dysplasia (BPD): see BPD

Byssinosis (brown lung): see Occupational Respiratory Diseases

Chest tumors: see Chest Tumors

Chronic bronchitis: see Chronic Obstructive Pulmonary Disease

Chronic sinusitis: see Sinusitis & Rhinitis

Colds: see The Common Cold

COPD: see Chronic Obstructive Pulmonary Disease

Coronaviruses: see Coronaviruses

Croup: see Croup

Cystic fibrosis: see Cystic Fibrosis

Dust allergies: see Dust Allergies

Emphysema: see Chronic Obstructive Pulmonary Disease

Flu: see Influenza

Hay fever: see Pollen Allergies

Hypopharyngeal cancer: see Head and Neck Cancers

Influenza: see Influenza

Laryngeal cancer: see Head and Neck Cancers

Legionnaires' disease: see Legionnaires' Disease & Pontiac Fever

Lung cancer: see Lung Cancer

Lupus: see Lupus

Mold allergies: see Mold Allergies

Nasopharyngeal cancer: see Head and Neck Cancers

Nonallergic rhinitis: see Sinusitis & Rhinitis

Occupational lung disease: see Occupational Respiratory Diseases

Oropharyngeal cancer: see Head and Neck Cancers

Paranasal sinus cancer: see Head and Neck Cancers

Pertussis (whooping cough): see Childhood Illnesses

Pleurisy: see Pleurisy

Pneumoconiosis: see Occupational Respiratory Diseases

Pneumonia: see Pneumonia

Pneumothorax: see Pneumothorax

Pollen allergies: see Pollen Allergies

Pontiac fever: see Legionnaires' Disease & Pontiac Fever

Pulmonary embolism: see Pulmonary Embolism

Pulmonary hypertension: see Pulmonary Hypertension

Respiratory distress syndrome in infants (RDSI): see RDSI

Respiratory distress syndrome, acute: see Acute Respiratory Distress Syndrome (ARDS)

Respiratory syncytial virus (RSV): see Respiratory Syncytial Virus (RSV)

Rhinitis: see Sinusitis & Rhinitis

Rose fever: see Pollen Allergies

SARS: see Severe Acute Respiratory Syndrome (SARS)

Scleroderma: see Scleroderma

Sinusitis: see Sinusitis & Rhinitis

Sore throat, strep throat: see Sore Throat & Strep Throat

Tracheal tumors: see Tracheal Tumors

Tuberculosis: see Tuberculosis

Whooping cough (pertussis): see Childhood Illnesses

All Concept Communications material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.

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By printing and/or reading this article, you agree that you accept all terms and conditions of use, as specified online.