1.2.3: A healthy, active lifestyle and your respiratory system L.O 1.Understand the structure of the lungs 2.Understand the function of the respiratory system

The respiratory system is everything we use to breath.

You need to be able to understand how we breath to get oxygen into the body and to get rid of waste carbon dioxide.

The Trachea is split up into two bronchus that leads into both our lungs. The bronchi are further distributed into bronchioles. The air travels along these tubes and finally ends up in the air sacs (alveoli).

The air sacs are surrounded by a network of capillaries and as the blood flows through these capillaries, the oxygen in the air sacs(alveoli) diffuse into the blood, thus reoxygenating them.

The diaphragm As we breathe in (Inhale), the diaphragm contracts and depresses so that a lot of air enters and fills up the lungs. The ribs are therefore raised. The Diaphragm moves downwards When we breathe out (Exhale), the ribs return to their original position and the diaphragm relaxes and arches upwards. The air is forced out of the lungs and returns the same way it came.

The path the air takes back out is very similar, except that this time round, the blood meets the air sacs and carbon dioxide diffuses out. This carbon dioxide finally returns to the atmosphere when we exhale.

How we breath Inspiration - Breath in When you inhale: the intercostal muscles contract, expanding the ribcage. the diaphragm contracts, pulling downwards to increase the volume of the chest. pressure inside the chest is lowered and air is sucked into the lungs.

How we breath Expiration - Breath out When you exhale: the intercostal muscles relax, the ribcage drops inwards and downwards the diaphragm relaxes, moving back upwards, decreasing the volume of the chest. pressure inside the chest increases and air is forced out.

Gaseous exchange Gas is exchanged from the air into the blood stream in the alveoli (tiny air sacs). Waste carbon dioxide is transferred from the blood back into the air also.

Respiration Respiration is the release of energy from glucose in the muscles. When the body is at rest this is aerobic respiration. As you exercise you breathe harder and deeper and the heart beats faster to get oxygen to the muscles. Glucose + oxygen → energy + water + carbon dioxide

Respiration When exercising very hard, the heart cannot get enough oxygen to the muscles. Respiration then becomes anaerobic. Glucose → energy + lactic acid Vital capacity is the most air you can breath in or out in one breath.

Short term effects 1.You breath more quickly 2.You also breath more deeply (take in larger volumes of air each breath) 3.If your doing anaerobic activity then lactic acid will begin to build up in your muscles 4.When you stop exercising anaerobically your body will continue to breath heavily to get rid of the lactic acid by repaying the 'oxygen debt'. 5.Respiratory rate increases. The number of breathes per minute

Long term effects 1.The muscles around your chest cavity get stronger - so they can make your chest cavity larger 2.With a larger chest cavity you can breath in more air in one breath (increase vital capacity)

Long terms effects 3.Your lungs get more efficient at exchanging gas into and out of the blood stream. 4.Develop more alveoli so greater gaseous exchange can take place 5. This means you have a better oxygen supply to the body which means you should be able to exercise for longer.