Maladies (4) – Asthme

La série sur la maladie se poursuit avec l’asthme (asthma). Vous trouverez sur Wikipedia en anglais simplifié un article très complet, avec des schémas et vous pourrez même écouter la respiration d’un asthmatique (wheezing) au stéthoscope.

Ici, je vous propose quatre schémas ou infographies. (Les termes marqués comme des hyperliens sont expliqués en infobulles : placez le curseur dessus pendant une à deux secondes) :

A. Pourquoi l’asthme rend-il la respiration difficile ?
Air enters the respiratory system from the nose and mouth, and travels through the bronchial tubes.
In an asthmatic person, the muscles of the bronchial tubes tighten and thicken, and the air passages become inflamed and mucus-filled, making it difficult for air to move.
In a non-asthmatic person, the muscles around the bronchial tubes are relaxed and the tissue thin, allowing for easy airflow.

B. Les déclencheurs de l’asthme.

C. Le déclenchement d’une crise d’asthme (anglais UK).
Asthma triggers are factors that bring on the symptoms or an attack by irritating the airways or worsening the inflammation in the airways. These triggers can provoke attacks in individuals who already have a tendency to asthma:

1. Infections, usually by a virus (colds, flu)
2. Allergens, most commonly house dust mites, pets or pollen grains
3. Certain medications (aspirin)
4. Smoking, irritants such as air pollution, sulphur dioxide and diesel fumes
5. Strong smells, perfumes
6. Changes in the weather, high humidity
7. Emotions like anger, fear or excitement as well as food additives such as tartazine (an artificial food colouring agent) can also kickstart an attack.

D. Les crises d’asthme.
Attacks usually start as an allergic reaction to pollen, smog, or another substance mistaken for a threat by the body’s defense system.
How the lungs work:

• Fresh oxygen inhaled
• Travels through bronchial tubes
• Oxygen enters blood through thin alveoli walls
• Carbon dioxide passes from blood into alveoli and exhaled from body.

Asthma attacks:
What can keep air from entering / leaving the lungs:

1. Muscles surrounding airways tighten to constrict them
2. Inflammation of lining shrinks passageway
3. Excess mucus blocks airway

Pour conclure, je vous conseille la consultation du dossier sur l’asthme de l’OMS en anglais (Il existe aussi en français.)