“The Aortic Pump”

When Monica and Chandler are planning to adopt a baby, and wisely recruit good friend Joey to write a letter of recommendation:

Monica: It doesn’t make any sense.
Joey: Of course it does. It’s smart! I used a thesaurus!
Chandler: On every word?
Joey: Yep.
Monica: All right, what was this sentence, originally?
Joey: Oh. “They’re warm, nice people with big hearts.”
Chandler: And that became, “They’re humid, pre-possessing homo-sapiens with full-sized aortic pumps?”

The heart was personally the most interesting organ to learn. Not because I kept humming Backstreet Boys’ love ballads or thinking about 2pm’s “Heartbeat” MV during that dissection, but more that this one power pump bears the burden and blessing to maintain life.

Back in high school and college biology, I only had to learn the chambers and chief arteries entering and exiting the heart. Now I can name all the coronary arteries encircling the singular heart from chamber to chamber, apex to base. The coronary branches hug the heart snuggly, like gift-wrapping for the holidays! There are the interventricular PDA (posterior/descending) and LAD (anterior/descending) branches longitudinally sectioning the heart and the right coronary (RCA, like the record company) and circumflex arteries burrowing in the atrioventricular sulcus. Like ribbon garnishings, the marginal artery runs along the edge of the RV, while the LV gets special treatment with finger-like diagonals and obtuse marginals. To top off the wrapping are the intertwining pulmonary arteries and aortic arch, the final bowties to cap life’s power generator.

 

Pure charms

In 2pm’s “Heartbeat” (off 1집 1:59PM-2009), the song begins “Can You Feel My Heartbeat… Heartbeat.. beat-beat-Heartbeat-beat-beat… [some Korean I don’t understand]” Taeyeon, Nikhyun, Junho, Junsu, Chansung, and Wooyoung slowly rise from the dead, resurrected for a performance. Jesus, they look pained and pissed-off… As part of the dance sequence, they sway limply and with clawed hands, not too far from a T-rex dance or MJ’s “Thriller” moves. To me, they look like drugged-up zombies who make Asian girls melt. After, they cross their arms over their heart and pump their chests.  In their hands lies an invisible, beating heart.  The difference between 2pm and me, besides the fact I’m not a knockout Korean dancer with a chiseled 6-pack, is that I held a heart in my palms. Well, a preserved one at least. It is truly amazing to hold the heart in your hands (albeit lacking the rhythmic beatings) and trace the circulation with a probe. One point I’d like to make, the heart is not the size of a fist, as that has been the generalization in Bio 101. My fist may be small, but the cadaver’s fist certainly was not big enough to render it a good estimation of his heart size.

As it is well known, the heart does not look like the cultural symbol, the one that resembles butt cheeks on the top before narrowing down to a sharp V for Valentine. Rather, it’s irregularly shaped, more rounded, with grooves (“sulcus”) and tortuous arterial networks. And interestingly, the heart slants slightly to the left, the right side appearing more anterior and close to the sternum. It’s not like you can see all four chambers and vessels from a dead-on viewpoint; you’d have to twist your head and burrow in to see all the compartments.

Aside from dominance in the brain, did you know you have heart dominance as well?  Right and left dominant hearts depend on where the posterior descending artery (PDA) branches, either off the RCA or the LCA’s circumflex artery.

What a colorful mess of a circulation!

The sinoatrial (SA) node equals the pacemaker and power button to every heartbeat. More amazingly, the insides are truly spectacular. Pectinate muscles only appear in the right atrium, striated strips bolstering the chamber that receives venous blood from the entire body. The trabeculae carnae muscles lining the powerful ventricular walls remind me of those African savannah carnages the Discovery channel filmers love to get up close and personal. I laugh when I envision the trabeculae carnae because my lab-mate and friend Jason likens the carnae muscles to a scene out of the Legend of Zelda involving a Lord Jabu-Jabu. I googled searched and found Lord Jabu-Jabu’s walls to be exactly like the trabeculae carnae. Forever will I remember this connection (and those zebra corpses and bloodied Mufasas licking their lips in triumph) and refer to trabeculae carnae as the “ventricular walls of Lord Jabu-Jabu.”

My doodles

Finally, I’ve gotten my tricuspid and mitral valves straight. Always, I forgot which side the valves sat, but an amazing mnemonic boosted my poor memory:  You try and get it right = tricuspid valve on the right side between atrium and ventricle. The ventricles require much support for its hefty job. The delicate cusps of the valves connect to the strumming, stringy chorda tendinae, which in turn strap onto powerful papillary muscles. Along the ventricles is the moderator band, the ‘middle man’ holding together the papillaries =)

More doodles

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