Why does heart rate increase in inspiration?

[scilearner]

Hello everyone,

 

Can anyone explain simply why heart rate increases in inspiration. Also why does the aortic valve close before pulmonary valve in inspiration? In inspiration does superior vena cavae get more blood? From what I read there was something to do with blood pooling inside the lungs during inspiration? Why does blood pool I don't understand?

 

Thanks

Edited January 15, 2010 by scilearner

[Capita]

heart rate increases because increased co2 levels in the brain tells the pons and the medulla to increase the heart rate to rid the body of higher co2 levels more specifically increased co2 levels are managed by the pontine respiratory centers, ventral repiratory group, and the dorsal respiratory group in the pons and the medulla. The blood will gather in the pulmonary veins because they exchange gas. The pulmonary veins of the lungs will dilate if higher o2 levels are found in the body in order to let less o2 in and let it be used in order to gain higher co2 levels this will also increase blood around the lungs.