respiratory system

• Lung volumes: calculated with

  Spirometer
• Tidal volume


  The volume of air inhaled /exhaled per breath (500ml)
• Tidal volume


  Increases with exercise
• Inspiratory reserve


  Volume of air that can be forcibly inspired per breath, decreases with exercise
• Expiratory reserve


  Volume of air than can be forcibly expired per breath, slightly decreases with exercise
• Residual volume


  Volume of air that remains in the lungs after maximum expiration, always stays the same
• Vital capacity


  Tidal volume + inspiratory reserve + expiratory reserve
• Respiratory centre


  • Receives information from chemoreceptors (CO₂ and pH levels), baroreceptors (blood pressure), stretch receptors (in the lungs), vagus nerve
• Respiratory centre


  Increases breathing frequency and depth
• Phrenic nerve


  • Causes inspiratory muscles to contract
• Diaphragm


  • Will contract faster and stronger
• Intercostal muscles


  • Stimulated more frequently
• Sternocleidomastoid


  • Further increase the depth of inspiration
• Abdominals


  • When expiration becomes active
• Sympathetic nervous system


  Increases frequency and depth of breathing
• Parasympathetic nervous system


  Decreases frequency and depth of breathing
• Carbon monoxide


  Has a higher affinity than oxygen so it binds with haemoglobin
• Smoking


  • Constricts bronchioles, damages cilia (cleans the lungs), alveoli decrease, impacts gaseous exchange, decreases O₂ utilisation, aerobic capacity, causes chronic obstructive pulmonary disease, lung cancer
• Smoking causes mucus / tar build up in the lungs, damaged alveoli (emphysema), coronary heart disease (atherosclerosis)