My little bottles of helpers"

A row of bottles on my shelf

Caused me to analyse myself

1 yellow pill,1 hour to pop

Goes to my heart so it will not stop,

A little white that I take

Goes to my hands so they won't shake.

The blue one I like and use a lot

Tell me I'm happy but not really!

The purple pill goes to my brain

and tells me that I have no pain.

The capsules tell me not to wheeze

Or cough or chock OR even sneeze.

The red ones,smallest of them all

go to my blood so I won't fall.

The orange ones,very big and bright,

Prevent my leg cramps in the night.

Such an array of brilliant pills,

But what I would love to know

Is what tells each one where to go!!!!!?????