Q1. What happens to the chest cavity when we breathe in and breathe out?
1 It comes out (expands) when we breathe in and goes in (contracts) when we breathe out.
2 It goes in (contracts) when we breathe in and comes out (expands) when we breathe out.
3 There is no change in the chest size when we breathe in and out.
4 Cannot say from the above information.
Q2. Muscles that are not under our control are called involuntary muscles. Which of these is an action performed by 'involuntary muscles'?
1 pushing a trolley in the super market with our hands
2 pushing food through the food pipe to the stomach
3 picking up a pencil with our fingers
4 kicking a ball with our feet