3 Maintenance System RESPIRATORY URINARY &

Respiratory and circulatory systems Although you don’t have to think about breathing, it is essential for your survival. It is a necessary function so that you can meet oxygen requirements for cellular respiration and for the removal of waste products such as carbon dioxide. Cells need energy! Your circulatory and respiratory systems work together to provide your cells with oxygen which is essential for cellular respiration. This process involves the breaking down of glucose so that energy is released in a form that your cells can then use. As can be seen in the cellular respiration equation below, carbon dioxide is produced as a waste product. The carbon dioxide then needs to be removed from your cells or it would cause damage or death to them. Glucose + oxygen carbon dioxide + water + energy 3.1 Lung Nose Oxygen Trachea Bronchi Bronchioles Alveoli Organs of the respiratory system, expanded to show details Getting oxygen into your respiratory system Your respiratory system is responsible for getting oxygen into your body and carbon dioxide out. This occurs when you inhale (breathe in) and exhale (breathe out). When you breathe in, you actually take in a mixture of gases (of which about 21 per cent is oxygen) from the air around you. The air moves down your trachea (or windpipe), then down into one of two narrower tubes called bronchi (bronchus), then into smaller branching tubes called bronchioles which end in tiny air sacs called alveoli (alveolus