Why does a pulse increase when standing from sitting?

Exertion.

Even the slightest bit of exertion (such as standing up) will cause a slight quickening of the pulse. The amount your pulse quickens depends a lot on your level of physical fitness.

thanks a lot the girlie who said exertion lol =]

yes your hart rate will chang

your heart has to work harder when you are standing up because of what is known as veinous pooling. Basically, gravity causes the blood to move toward your feet so the heart has to work harder to pump it around your body.

Hi dude,I am a medico and I have tried my best to make my answer simple.I sincerely hope not to bore you. Baro receptors situated in the carotid sinus of the carotid artery, in the neck play a main role in reducing the blood pressure. They are activated only by increased blood flow to all parts of body,implying increased blood flow to the carotid sinus. Reduced blood flow causes the opposite effect- increase in blood pressure. When you stand up after sitting, blood return(venous return) to the heart is reduced due to gravity. Only less blood is returned from the parts of body lower in position than the heart. So lesser blood is pumped from the heart and reaches the carotid sinus. Lesser blood flow causes increased blood pressure. Blood pressure is directly related to pulse and so pulse also increases.