respiratory system Flashcards
what is the function of the respiratory system
it is an air distributor and gas exchanger. transports O2 and CO2.
what is the only part of the RS not to act as an air distributor
the aveoli
what other 3 functions does the RS do
filters// warms// humidifies
what are the 2 main parts of the RS and what structures do they contain
upper tract = nose// pharynx// larynx
lower tract = trachea// bronchi// bronchioles// aveoli
what is the functional unit of the lungs
aveoli
what are the 2 phases of respiration
inhalation// exhalation
describe inhalation
the diaphragm flattens causing a -ve pressure (759mm Hg) in the lungs which means that air is sucked in from the atmosphere// The lungs expand// rib cage expands// sternum rises.
describe exhalation
the diaphragm expands causing a +ve pressure (761mm Hg) in the lungs// air is pushed out of the lungs// the lungs deflate// the rib cage lowers// the sternum drops.
what is normal atmospheric pressure that respiration has to overcome
760mm Hg (mercury)
