The needle pierces my flesh, I can't look. The throbbing sensation reaches a crescendo.
Approximately 5 litres of blood is traversing my circulatory system at a rapid rate and I'm feeling just a little queasy. I've never been a huge fan of diagnostic blood letting but deep within my tissues, these biconcave crimson cells may hide the reason for my lethargy.
Distribution of precious oxygen molecules throughout my tissues will eventually contribute to the creation of energy, much needed when chasing after a small (grubby) child.
Clearly, as highlighted by my continual yawning, my mitochondria are feeling oxygen deprived. Or perhaps, the little white soldiers that patrol the depths of my insides are overwhelmed by an ambush of viral invaders.
Either way, the tubes of scarlet liquid that line the desk in the phlebotomy clinic are the true essence of life.