The human heart is an incredible organ.
The average human heart beats about 72 times a minute, approximately 2.5 BILLION times in an average 66 year lifespan, and pumps approximately 4.7 – 5.7 liters of blood per minute.
Ready to rock out to Nick, Howie-D, and the Boys? Turn it up, you know you want to …
Does A.J. make your heart go pitter-patter, does Kevin get you all hot and bothered, or do the whole lot of them make you want to put your fist through your computer screen? This is in part because of your Autonomic Nervous System (ANS).
The ANS is part of the peripheral nervous system that acts as a control mechanism for functions that are (for the most part) out of our conscious control including:
- Heart Rate
- Respiratory Rate
- Pupillary Dilation
- Micturation (urination)
- Sexual arousal
In the brain, the ANS is located in the medulla oblongata (such a lovely word to say…oblong-aaaaah-tah) in the lower brainstem where it functions include respiratory, cardiac, vasomotor, and reflex control centers. However, let us just consider the heart for the moment.
The ANS is further divided:
- Sympathetic – “Fight or Flight” Response which corresponds with arousal and energy generation, and inhibition of digestion
- In the Heart activation of the sympathetic nervous system increases heart rate and the contractility of cardiac cells, thereby providing a mechanism for enhanced blood flow.
- Parasympathetic – “Rest and Digest” response promotes calming of the nerves return to regular function, and enhances digestion.
- Dedicated cardiac branches of teh vagus and spinal accessory nerves impart parasympathetic control of the heart to slow heart rate, decrease contractility, and relax smooth muscle.
In any given day our ANS pulls many strings to keep us in homeostasis (balance) but next time your heart races at the thought of someone or something…remember that it is just your Autonomic Nervous System just playing games with your heart.
(OK, you now have permission to rock out to the rest of the Backstreet Boys’ album…don’t worry, I won’t tell 😉 )