Human breathing Flashcards
what is stage one of breathing in?
inhalation begins when the diaphragm contracts
what is stage two of breathing in?
the contraction pulls the diaphragm down
what is stage three of breathing in?
external intercostal muscles contract, raising the rib cage
what is stage four of breathing in?
the volume of the chest cavity increases
what is stage five of breathing in?
the pressure inside the pleural membrane decreases
what is stage six of breathing in?
air moves from an area of high pressure to an area of low pressure inside the lungs
what is stage one of breathing out?
contraction of the diaphragm ends so the diaphragm relaxes and moves up
what is stage two of breathing out?
external intercostal muscles relax, lowering the rib cage
what is stage three of breathing out?
the volume of space inside the lungs decreases
what is stage four of breathing out?
the pressure inside the lungs is greater than the pressure outside
what is stage five of breathing out?
air is pushed out of the lungs, down the pressure gradient
what is the extra step that can occur when breathing out?
internal intercostal muscles may also contract during intense exercise, coughing or sneezing
How do you work out the pulmonary ventilation rate?
Tidal volume X breaths per minute
How do spirometers make a trace?
Chamber filled with oxygen resting on water
Breathes in and out of chamber causing lid to rise and fall as volume changes
Pen attaches to spirometer draws a trace on a rotating drum
What is meant by the term maximum pulmonary ventilation?
The total volume of air that passes through the lungs in a given time
