Pulsing vein

 A pulsing vein

visible at the wrist 

is telling a story

if you want to listen.

Heart's emissaries;

aorta and arteries have delivered oxygenated blood to the remotest muscle and ligament and organs of your body making it possible

for your fingers write,

your toes flex, your brain to function, 

your eyes to blink. 

unaware of the infinitesimal changes

Just under your skin

 you have now depleted the oxygen, your blood needs a recharge

 that vein you saw pulsing

 takes your deoxygenated blood

 back to the heart.

 ah right, you now

 go back to fiddling with your phone

Prompt: explain something in your poem