respiratory system Flashcards
definition of tidal volume
amount of air normally breathed in/out with each breath
definition of minute ventilation
volume of air inspired/expired each minute
definition of residual volume
volume of air that remains in the lungs after maximal expiration
definition of expiratory reserve volume
amount of air that can be expired on top of the tidal volume
definition of inspiratory reserve volume
amount of air that an be inspired on top of tidal volume
definition of vital capacity
maximal volume of air that can be expired following maximal inspiration
definition of total lung capacity
amount of air that can be held in the lungs following maximal inhalation
typical resting value of tidal volume
500ml
typical resting value of minute ventilation
6.0l/min
typical resting value of residual volume
1,200ml
typical resting value of expiratory reserve volume
1,200ml
typical resting value of inspiratory reserve volume
3,100ml
typical resting value of vital capacity
4,800ml
typical resting volume of total lung capacity
6000ml
what does the respiratory system consist of
number of structures which allow gases to be transferred between the body and the external environment
when gasous exchange important
when large volumes of o2 are required by the muscles and the large volumes of co2 need to be removed from the body
what is the order that air travels through the body
nasal cavity
oral cavity
pharynx
larynx
trachea
bronchi
bronchioles
alveoli
gas exchange at the alveoli
o2 moves from high concentrated the aveoli areas to an area of low pressure the blood
gas exchange is efficient due to
large number of alveoli
large numbers capillaries
thin membrane between he alveoli and capillary
gas exchange at the muscles
when exercising their is a high atreiovenous difference which increases the pressure gradient for gas diffusion
definition of arteriovenous difference
the amount of o2 taken up from the blood by tissues, the higher the o2 taken the bigger the difference
what happens to the diaphragm during inspiration
contacts and becomes flatter causing the lungs to be pulled downwards
what happens to the external intercostal muscles during inspiration
contract causes the ribs to move up and out allowing the thoracic cavity to enlarge in volume
what happens to air pressure during inspiration
larger lung volume decreases the lungs sir pressure below that of the atmospheric air causing air to enter the lungs from the atmosphere
what happens to change in exercise during inspiration
sternocleidomastoid and pectoralis major lift the ribcage further upwards and outwards
what happens to the diaphragm during expiration
relaxes moving upwards
what happens to the external intercostal muscles during expiration
muscles relax causing ribs to move downwards and inwards reducing the thoracic cavity volume
what happens to air pressure during expiration
lower lung volume increases the lungs air pressure above that of the atmospheric air causing air to be expelled from the lungs into the atmosphere
what happens when change in exercise in expiration
internal intercostal and rectus andominus contract forcing the ribcage downwards and inwards
what is gaseous exchange
where co2 diffuses from high concentration of blood to low concentration.
oxygen also disassociates from haemoglobin though diffusion, a low concentration of oxygen in the working muscles means oxygen diffuses down the concertino gradient and into the muscles.
what is breathing frequency
the number of berths per minute.
what is partial pressure
is the individual pressure that a gas exerts in a mixture of gases
explain the role of pressure gradients in ventilation
-air moved from areas of high pressure to areas of low pressure
-pressure gradients allow air from outside of the body to rush into repiratory tract during inspiration
-diaphragm contracts which reduces the pressure inside the lung and thoratic cavity
-the reduced pressure causes a pressure gradient allowing air to venter the lung
-diaphragm relaxes increasing pressure inside the lung/thoracic cavity
-the increased pressure inside the lung forces the air out
-reduced barometric pressure reduces pressure gradient
