Biology
Exploring the effects of disease and lifestyle
We are learning how to: • Describe the physical effects of disease and lifestyle on the breathing system. • Explain the physical effects of disease and lifestyle on the breathing system. • Describe how our understanding about the effects of smoking has changed over time.
The breathing system can be affected by both lifestyle choices and disease. We can't choose about inheriting a disease, but we do have a choice about whether or not we exercise or smoke. Lifestyle choices and disease
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Regular exercise improves breathing. It increases the strength of intercostal muscles so the chest can expand more when you breathe in, so your lung volume increases. It also increases the number and size of the blood capillaries surrounding the alveoli, so more oxygen can reach cells for respiration. Diseases such as asthma affect the breathing system negatively. Asthma is thought to be influenced by inheritance, being born prematurely and being exposed to smoking in the womb or as a young child. 1. Give examples of a lifestyle choice and a disease that affect the breathing system. 2. Describe two ways in which the bronchioles change during an asthma attack, making it hard to breathe.
air enters the respiratory system from the nose and mouth and travels through the bronchioles
bronchioles
in an asthmatic person,| the muscles of the bronchioles tighten and thicken, and the air passages become inflamed, making it difficult for air to move
in a non-asthmatic person, the muslces around the bronchioles are relaxed and the tissue thin, allowing for easy airflow
3. Describe two ways in which exercise affects the breathing system. inflamed bronchiole of an asthmatic
normal bronchiole
FIGURE 1.2.17a: Asthma makes it hard to breathe.
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KS3 Science Book 1: Eating, Drinking and Breathing
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09/12/2013 15:22