muscles
brains
hands
legs
their sense of balance doesn’t change
their sense of balance gets worse
their sense of balance gets better
migraines
motion sickness
food poisoning
sleeping sickness
walking
talking
interacting
eating
legs and arms
torso and head
stomach
lungs
nothing, it stays the same
it speeds up
it slows down
it swells with fluid before shrinking
microgravity
regular gravity
zero gravity