As an airplane rises through the atmosphere, machines cause the pressure inside the cabin to decrease. Why is this change in pressure necessary?

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

you should wear a lead protective shield when having teeth x-rays

hope i

-lavira : )

what about it?

is this a ?

answer; somatic;