The Heart.

As Valentine's Day is fast approaching, I present you with some basic information about the anatomy of the heart. Note: I've spent the whole week learning about the heart, so obviously there is much more than I am presenting today. This is just an sample/taste/amuse-bouche, if you will :P

- It is slightly larger than a clenched fist.
- 2/3 of the heart is position on the left side of the thoracic cage, while 1/3 is on the right side of the cage. Also, the left side of the heart is thicker than the right.
- When lying down, the apex (or tip) of the heart comes in closest contact with the chest wall. Thus, in order to best feel the heart beat, lie down and you should be able to feel your heartbeat strong and clear.
- The outside of the heart features two auricles (they are the pink colored parts of this image). This finger-like projections (or, as described by my Anatomy prof, are like the arms of Patrick (the auricles) giving SpongeBob (the heart) a big hug... he then remarked that he is constantly amused at his ability to "stupidify" Anatomy). The role of auricles to prevent the heart from over-expanding (say, for instance, someone stepped on your stomach, you don't want the heart to explode from the excess blood and pressure that suddenly is moving upwards. Sorry; that was kind of a crude description :P).
- The heart pumps blood in a figure 8 sort of loop. Blood enters the right side of the heart, is pumped into the pulmonary circulation to travel through the lungs to pick up oxygen, returns to the left side of the lung, and is finally pumped out to the rest of the body via systemic circulation. However, fetuses don't pump blood into the lungs as the amniotic fluid contains all the oxygen they need. Only after their first breath of air (after birth) do babies start pumping blood into the lungs for oxygenation.

<3