Iam a relatively fast-acting chemical messenger that affects mood, hunger, sleep, and arousal. what am i?

answer; //the above statement is (false);

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.

yes we can.   a lady urinates from her urethra.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added