The Respiratory System

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The Respiratory System

• GCSE

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Learning Outcomes

• By the end of todays lesson you should
• Be aware of what respiration is and its
  components
• Be aware of the process involved when we inhale
  (breathe in) and exhale (breathe out).
• Know the difference between aerobic and anaerobic
  respiration
• Be familiar with the term Gaseous Exchange.

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What is Respiration?

• Respiration is the process in which glucose is
  converted into energy useable for life processes.
  
• Respiration involves the important component of
  breathing but be careful not to confuse
  respiration as just solely breathing.
• There are 2 types of respiration that our bodies
  use for different activities...

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Aerobic Respiration
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Anaerobic Respiration
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What is the difference between Aerobic and
Anaerobic Respiration?

• Q. Aerobic respiration occurs in the presence
  of...
• A. Oxygen
• Example of an Aerobic activity Marathon Running
• Q. Anaerobic respiration occurs in the ABSENCE
  of...
• A. Oxygen
• Example of Anaerobic activity 100m Sprint

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Aerobic Respiration

• Aerobic respiration occurs in the presence of
  oxygen and is summarised by the following
  equation
• Glucose Oxygen ? Energy Carbon Dioxide Water
  
• This type of respiration is used when the body
  continues an activity for a prolonged period of
  time.
• The energy that is needed to allow this prolonged
  activity is produced using oxygen.

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Aerobic Respiration Cont

• In order for the aerobic system to function
  effectively, there has to be a constant supply of
  oxygen to the body and the working muscles.
• For any activity that takes place over a long
  period of time (e.g. Marathon) it is important to
  have this constant supply of oxygen to the body
  otherwise the body would be unable to carry out
  the event.

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Anaerobic Respiration

• On the other hand, anaerobic respiration is the
  process where energy is made in the absence of
  oxygen.
• The equation for anaerobic respiration is
• Glucose ? Energy Lactic Acid

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Anaerobic Respiration Cont.

• This type of respiration occurs when the body
  works without sufficient oxygen being delivered
  to the muscles.
• Without the presence of oxygen, a waste product
  called lactic acid is produced in the muscles.
• High lactic acid concentrations cause muscles to
  feel painful and can lead to cramp.
• As oxygen is not being used to generate energy in
  anaerobic respiration, it can only be used for
  short bursts e.g. 100m sprint

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Aerobic or Anaerobic?
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Aerobic or Anaerobic?
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Aerobic or Anaerobic?
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Aerobic or Anaerobic?
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Aerobic or Anaerobic?
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Aerobic or Anaerobic?
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Oxygen Debt

• When our bodies respire anaerobically during
  vigorous exercise, supplies of oxygen are reduced
  to working muscles.
• As there is an absence of oxygen, the body can
  only respire anaerobically for a maximum of 60
  seconds.
• During an anaerobic event such as the 100m sprint
  or a 50m freestyle event in swimming, our bodies
  will effectively borrow oxygen and it will need
  to paid back in order to break down the waste
  products produced (lactic acid).

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Oxygen Debt

• For example, Usain Bolt runs the 100m race in
  under 10 seconds and after the race finishes, he
  must continue to breathe deeply and heavily in
  order to replenish the oxygen or pay the oxygen
  debt.
• One of the main reasons for completing a cool
  down after vigorous exercise is to enable the
  oxygen debt to be repaid and will allow any
  lactic acid to disperse which will avoid further
  discomfort.

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The Recovery Period

• Following intense exercise we have to take in
  extra oxygen which will help convert the lactic
  acid into simple waste products that have to be
  removed from the body.
• Expiration of breath removes the carbon dioxide
  and other waste products from our lungs.
• Perspiration is a form of temperature control
  and also removes excess water such as sweat at
  the same time that it is letting heat escape
  through evaporation from the skin. Although this
  heat is not really a waste product it must be
  released to prevent our bodies from overheating.
• Excretion through urine and faeces removes
  excess water and the other waste products from
  the lactic acid.

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Breathing
This is a diagram of all the components involved
in the breathing process
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Inhalation (breathing in)

• During inhalation
• The chest cavity changes shape and size.
• The intercostal muscles contract which causes the
  rib cage to expand and pushes out the sternum
  (chest/breastbone)
• The diaphragm will contract and will change shape
  from a concave or dome shape to a flattened
  shape.
• The pressure inside the chest cavity will be
  reduced and therefore allows air to be sucked
  into the lungs.
• The air we breathe in is high in oxygen and
  nitrogen but low in carbon dioxide.

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Diagram of Inhalation
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Exhalation (breathing out)

• During exhalation
• The process is virtually reversed
• The chest cavity changes in shape and size
• The intercostal muscles relax, allowing the rib
  cage to drop downwards and inwards.
• The diapgrahm relaxes and regains its concave or
  domed shape and this decreases the volume of the
  chest.
• The pressure inside the chest will subsequently
  increase and force air out. The air exhaled is
  high in nitrogen and carbon dioxide.

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Diagram of Exhalation
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Gaseous Exchange

• Gaseous exchange is the process where carbon
  dioxide is exchanged in the lungs for oxygen by
  diffusion.
• The carbon dioxide produced as a waste product of
  respiration must be exhaled from the body and
  more oxygen is needed through inhalation.
• Gaseous exchange takes place in the alveoli in
  the lungs.

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Gaseous Exchange Cont.
The diagram shows gaseous exchange occurring at
the alveoli in the lungs. The oxygen is taken
into the blood and carried to the heart to be
pumped around the body and the carbon dioxide is
exhaled as a waste product of respiration.
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Test
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True or False?

• Anaerobic exercise involves using oxygen to
  produce energy.
• A triathlon competitor will use aerobic
  respiration.
• Carbon dioxide is a waste product which causes
  discomfort and pain in the muscles.
• Anaerobic respiration will be used in activities
  which can last up to 1 minute.

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Questions???

• What is the Oxygen Debt?
• Give 3 examples of aerobic activities
• Give 3 examples of anaerobic activities
• Give 2 example of a sport that will use both
  aerobic and anaerobic respiration.
• What are the 2 main muscles/group of muscles
  involved in breathing and changing the shape and
  size of the chest.