The legend of Cardiac Cycle 

It is not deoxygenated blood that the Vena Cavas bring in
I know so you have been taught 
But hear me out, O meritorious one!
If I waste your time then forgive me not

What enters the atria on the right, is a sludge of broken dreams
A black tar of corrupted whims
A muck of tainted letch and grins
Indeed, a fluid darker than the darkest sins

In a blink of a diastole the darkness descends
Into a non suspecting ventricle it glides
Shuts the three cusps, diabolically timed
Capturing a chamber for its demons to thrive

But there’s a knight in shining armor, Oh there always is!
The gallant Purkinje fires, so does Bundle of His
The evil kicked out, what a stupendous fight
So don’t undermine the little Ventricle of the Right

Defeated, the murky sludge seeks a new ally
Began a journey north to see the Wizard of Alveoli
With every step ahead it pledged to return
Furtively conspiring to poison the heart it yearns

As the legend goes, or so I’ve been told
The Wizard of Alveoli was actually a warrior queen
Who lived in disguise in the land of Pulmonic Lobes
Silently and magically slaying evil, not many who knows 

‘Bestow upon me the souls of all hell’s fiends
Equip me so that I crush this human being’
This was all the satanic sludge day and night chanted
Hoping the Wizard would have his wish granted.

‘Here drink this concoction, it’s all you need’
Said the wizard queen, but the ingredients she didn’t reveal
Her hemoglobin goblins watched as the evil sludge drank
The elixir of oxygen, virtue and kindness, a necessary prank

Something changed or everything did
The darkness faded, the dark tar thinned 
All that was left was a new crimson light
Oxygenated, purified, ready for its flight

Like wine into a chalice, but without any malice
The light filled the atria 
Mitral greeted it with open doors
Not yet an end to this physiological folklore

The crimson light touched a new chamber
They call it the Great Ventricle of the Left from what I remember
Every bit worthy of a title so glorious
For it is not selfish, it spreads that light
Not just to his chum Aorta inside
But to systoling mortals worldwide 
Thus the essence of humanity and hope immortalized.