Respiratory SystemRespiratory System

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Respiratory SystemRespiratory System

• The respiratory system is mainly concerned with breathing

• The function of the respiratory system is to get oxygen into the body and carbon dioxide out of the body.

• The parts of the respiratory system are: air passages lungs diaphragm

Respiratory systemRespiratory system

Respiratory SystemRespiratory System

Passage of AirPassage of Air

• Enters the nasal cavity, here the air warms, moistens & is filtered.

• Air then passes into the larynx• Air is then passed down the trachea (windpipe)• Air then moves through the bronchi (left & right

bronchus)• Air then passes into the bronchioles• Air then goes into the alveoli

Gaseous ExchangeGaseous Exchange

Gaseous exchangeGaseous exchange

• The O² breathed in goes through the mouth or nose, down the trachea, into the lungs and into the alveoli.

• The O² passes through the alveoli walls into the red blood cells, via the capillaries.

• The O² joins with haemoglobin to make oxyhaemoglobin.• The oxyhaemoglobin is used by the working body and is transported

by the circulatory system to cells needing to release energy.• CO² is produced as a waste product• This is converted into a gas and passes back through the alveoli

walls, via the capillaries into the blood plasma.• Blood takes it back to the capillaries in the lungs.• CO² passes through the capillary and alveoli walls into the alveoli.

• It is then exhaled from the body.

Mechanism of BreathingMechanism of Breathing

Inspiration• Diaphragm pulls down• Intercostal muscles

contract• Air pressure is reduced• Air is sucked through the

tubes into the lungs• Chest expands

Expiration• Diaphragm relaxes into

its dome position• Intercostal muscles relax• Chest becomes smaller• Pressure increases on

lungs• Air is forced out

Composition of AirComposition of Air

Inhaled

• 79% = Nitrogen• 20% = Oxygen• Trace = Carbon Dioxide

Exhaled

• 79% = Nitrogen• 16% = Oxygen• 4% = Carbon dioxide

DefinitionsDefinitions

Vital CapacityThe maximum amount of air that can be forcibly exhaled,

after breathing in as much as possible.Residual VolumeThe amount of air left in the lungs after a maximal breath.Respiratory RateNumber of breaths per minuteTidal VolumeAmount of air breathed in or out at restMinute VolumeVolume of air breathed in, in 1 minute.

Respiratory System during exerciseRespiratory System during exercise

• Tidal volume increases

• Breathing rate increases and becomes deeper and more regular

• Heart beat increases, supplying the demand for more O² in the working muscles

• Gaseous exchange in alveoli increases

Respiratory SystemRespiratory System

Long-term effects of training on the respiratory system

Endurance

• Increased training makes gaseous exchange in the alveoli more efficient.

• Muscles are able to work at a harder level for longer without tiring – increasing the vital capacity of the lungs.

Interval over short distances at high speeds

• New capillaries are formed, heart muscle is strengthened and delivery of O² improves.