respiratory system

• respiratory system: get oxygen in the body and carbon dioxide out
• oxygen is needed by working muscles for respiration to create energy from glucose
• Carbon dioxide is a by product of exercise and needs to be exhaled as high levels are toxic
• The air you breathe in is 21% oxygen and 0.4% carbon dioxide
• The air you breathe out is 17% oxygen and 4% carbon dioxide
• During inhalation the diaphragm contracts (flattens) to pull air in
• during exhalation, the diaphragm relaxes so it becomes dome shaped again which pushes air out
• during inhalation the thoracic cavity increases in volume
• During exhalation the thoracic cavity decreases in volume
• During inhalation the ribs move up and out because of the intercostal muscles
• During exhalation the ribs move in and down
• During inhalation air moves into the lungs
• During exhalation air moves out of the lungs
• Tidal volume is the volume of air inspired and expired in a normal breath
• During excercise tidal volume increases from around 500ml to 3 litres
• Vital capacity is the total volume of air that can be forcibly exhaled after maximum inhalation (4-5litres)
• If you are fitter, vital capacity increases due to greater strength of the respiratory muscles
• Minute ventilation is the volume of air inspires/expired per minute
• Tidal volume x frequency = minute ventilation
• the nasal cavity Filters the air to remove dust, warms the air to body temperature, moistens the air to aid respiration
• gas exchange: The delivery of oxygen to the lungs (alveoli)to the bloodstream (capillaries) and the removal of carbon dioxide from the tissues
• Gas exchange happens by diffusion
• Regular aerobic training will increase the number of alveoli she capillaries available for gas exchange
• An increase in alveoli means more oxygen is in the blood which can be used for aerobic respiration
• Aerobic respiration : oxygen + glucose -> carbon dioxide + water + energy
• Anaerobic respiration : glucose -> energy + lactic acid
• Aerobic respiration is used for low intensity long duration activities such as running a marathon
• Anaerobic respiration is used for high intensity fast activities such as performing a serve in tennis
• Lactic acid fatigues muscles
• After anaerobic respiration there is an oxygen debt to remove lactic acid from muscles
• Aerobic respiration is 60-80% max HR
• Anaerobic respiration is 80-90% max HR
• Carbohydrates can be used as fuel for high intensity activities as their are stored in small amounts and broken down into glucose or glycogen for respiration
• Fats can be used for fuel for low intensity long duration activities since it is easy to store and can be broken down into fatty acids to produce glucose during aerobic respiration