The Respiratory System

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The Respiratory System

• and beyond

2
What does the respiratory system do?

• It provides our bodies with oxygen.

Oxygen

• The system removes and disposes of carbon
  dioxide.

Carbon Dioxide

• The body uses oxygen to allow the release of
  energy.

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The System

• The respiratory system consists of

• the Air passages

• the Lungs

• the Diaphragm.

4
What happens to the air you breathe?

• Air is inhaled through the mouth and nasal cavity
  (nose).

• Here cilia filter the air and it is moistened by
  mucus.

• It passes through the larynx and into the trachea.

• These branch into the bronchi.

• The air enters the lungs.

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How is Oxygen Absorbed?

• Each bronchus divides into bronchioles and then
  into tiny air sacs called alveoli.

• The alveoli are covered by capillaries.

• Here oxygen is exchanged into the blood and
  carbon dioxide taken out of the blood.

CO2 Out
O2 In
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How do we breathe?

• Inspiration is when we breathe in.
• Expiration is when we breathe out.

• The lungs are situated in a flexible sealed space
  called the thorax.

• At the bottom of the thorax is the diaphragm.

• As the chest expands the diaphragm contracts and
  pulls down creating a vacuum which allows air to
  enter.

• When the diaphragm relaxes the lungs contract and
  air is forced out.

• Breathing is both voluntary and involuntary, what
  does this mean?

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How do we measure breathing?

• Apart from running for the bus there are 5 tests
  of respiratory performance

• Vital Capacity. The maximum amount of air that
  can be breathed out (about 4.5 litres).

• Respiratory Rate. How many breaths we take
  depending on activity.

• Residual Volume. The amount left in the lungs
  (about 1.5 litres).

• Tidal Volume. The amount of air taken in or out
  depending on the size of the lung.

• Minute Volume. How much air is breathed in a
  minute (tidal volume x respiratory rate)

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What Happens During Exercise?

• More oxygen is needed in the muscles to release
  energy.
• Carbon dioxide needs to be removed.
• Respiration (breathing) must increase to meet the
  demand.
• The effects are

More blood is pumped through the lungs.

• Oxygen take up is increased.

• respiration Rate increases (breaths per minute)
  e.g from 12 to 36

• tidal Volume increases (litres per minute) e.g
  from 31 to 150.

Minutes of moderate exercise
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Are you fit? (healthy fit that is)

• Why is it that fit athletes hardly get out of
  breath while less fit people huff and puff?

• Athletes get fitter through training.

• Their bodies are able to use oxygen more
  efficiently.

• non athletes are at 65.

• They use the maximum amount of oxygen that can be
  used during exercise. This is known as V02 max.

• Very fit athletes such as middle and long
  distance runners work at about 85 of their
  maximum.

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Types of Energy system

• Aerobic is a sustained release of energy with
  oxygen for longer endurance events.

• There are two types of energy system.

• Anaerobic is the release of energy without oxygen
  for short bursts.

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How do these systems work?

• The body has to create energy chemically! BUT
  HOW?

• In the muscles is adenosine triphosphate (ATP).

• This is quickly converted to adenosine
  diphosphate (ADP).

• This is not sustainable and the body must use
  other chemicals to convert ADP back to ATP and
  continue the process of making energy.
• This is done in 3 ways.. .

• The by-product is Energy which is released.

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1. Anaerobic - Creatine Phosphate

• In the Anaerobic system the body produces energy
  by using two different chemicals.
• For very short bursts the body uses Creatine
  phosphate (CP).

• If you now stand and squat as quickly as you can
  10 times your body will use Creatine Phosphate.

• It will combine this with ADP to make ATP and
  energy will be given off.
• It doesnt need oxygen! So this is Anaerobic.

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2. Anaerobic - Lactic

• What happens if you continue with your squats for
  another 30 seconds?

• As you keep going you are in trouble.
• You can feel the burn of the lactic acid.

• Your body doesnt need oxygen yet. This is still
  Anaerobic!

• But you have just used your immediate supply of
  CP.

• You need oxygen to convert that lactic acid back
  to pyruvic acid.

• Your body will now start to use glycogen
• It will combine this with the ADP to make ATP and
  Energy.

• But your body also produces pyruvic acid which
  becomes lactic acid.

You are now in Oxygen Debt!
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3. Aerobic

• If you change activity to a a steady jog on the
  spot you will start to use a different system.

• You are now using your Aerobic system.

• You are still using glycogen from your body
  stores.

• But now the pyruvic acid is being broken down by
  the oxygen to produce water and CO2.

• The Aerobic system is used by anyone doing a
  sustained activity like jogging.

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Aerobic

• How long could you keep running for?

• As long as you keep a supply of oxygen it depends
  on your glycogen supply.

• The glycogen comes from the carbohydrates in your
  food.
• These are broken down and stored.

• As you tire your body will be using up the
  glycogen in your muscles and be looking for the
  other supplies like in fats.
• Endurance athletes will feel these body changes
  and look for warning signs (hitting the wall).

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Vocabulary
Do you know what these terms mean?

• Diaphragm
• Bronchi
• Bronchioles
• Alveoli
• Expiration
• Vital capacity
• Respiratory rate

• Tidal Volume
• Aerobic
• Anaerobic
• ATP
• ADP
• Creatine Phosphate
• Glycogen
• Lactic Acid

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Homework

• Complete the exam questions in the handout
  provided
• To be handed in next lesson