Respiratory system Flashcards
Function of the respiratory system?
- To bring in air/ Oxygen to the body from the external environment so oxygen can be delivered to the muscles and tissues.
- Expel carbon dioxide/ waste products from the body.
Nose (function)
Filters and warms the air with a mucus membrane and hairs (cilia)
Pharynx
Throat
Larynx
Voice box, meets the trachea
Epiglottis
- Tissue that covers the trachea so food goes down the oesophagus
- Ensures that food is diverted into the oesophagus and not the trachea.
Bronchi
Distribute air
Nasal passage
Humidify air
Diaphragm
Contracts and pulls air into the lungs
Inspiration (breathing in)- active process as it requires contraction
- External intercostal muscles contact causing the ribcage to move upwards and outwards
- Diaphragm which forms the floor of the thoraic cavity contracts downwards and flattens.
- These actions together cause an increase in the volume of the thoraic cavity and decrease in the pressure within the lungs.
- Pressure gradient ( high to low)
- Air moves into lungs
Expiration (breathing out)- passive process since no muscular contractions are involved
- External intercostal mucles relax causing the ribcage to move downwards and inwards
- Diaphragm relaxes causing it to rise
- These movements decrease the volume of the thoraic cavity
- Then pressure increases within the lungs
- Pressure gradient (high-low)
- Air is forced out of the lungs
Why do the internal intercostal muscles and abdominals contract during exercise whilst expiring?
- Breathing rates are increased during exercise
- So expiration is aided by the internal intercostal muscles and abdominal muscles
- These pull the ribcage down more quickly and with greater force
What is the difference between a lung volume and a lung capacity?
A lung capacity is made up of two or more volumes
Tidal volume (definition)
- Volume inspired or expired per breath
Tidal volume (typical value at rest)
500ml
What is the change of tidal volume during exercise?
It increases
Inspiratory reserve volume (definition)
Following inspiration the amount of air that you could continue to inspire if required.
Inspiratory reserve volume (typical value at rest)
3100ml
What is the change of inspiratory reserve volume during exercise?
It decreases
Expiratory reserve volume (definition)
Volume of air that remains in the lungs after expiration
Expiratory reserve volume (typical value at rest)
1200ml
What is the change of expiratory reserve volume during exercise?
It decreases
Residual volume (definition)
The amount of air that remains in the lungs after maximal expiration