ventilation in mammals Flashcards
what is inspiration
breathing in
what muscles contract during inspiration
external intercostal muscles and diaphragm
what does the muscles contracting in inspiration cause
ribcage to move up and down and the diaphragm flattens
why does the diaphragm flatten
increase the volume of the thorax where the lungs are located
as the volume in the thorax increases what happens to lung pressure
decreases below atmospheric pressure
what happens when lung pressure drops below atmospheric pressure
forces air to flow into the lungs
what type of process is inspiration
active requiring energy
which muscles relax during exhalation
external intercostal and diaphragm
what do the muscles relaxing in exhalation causing
ribcage moves down and inwards and diaphragm becomes curved
what happens to thorax volume during exhalation
decreases
what happens to the lung pressure when volume in the thorax decreases
air pressure increases above atmospheric pressure
what process is expiration
passive
when is expiration active
when it is forced
what happens during forced expiration
intercostal muscles contract, pulls ribcage down and in
what is tidal volume
the volume of air in each breath
