Why does caffeine increase heart rate?

Question

In laymans terms please!!

Answer 1

Well, to be specific, caffeine (like most pyschoactive drugs) exerts its effect on us by altering the activity of some of our neurotransmitters. Neurotransmitters are the nervous system's way of conveying messages between neurons, and also to muscle tissue. Some neurotransmitters that caffeine is known to increase the activity of are norepinephrine, dopamine, and serotonin. The increase in norepinphrine is likely what causes the heart rate to increase, however each of these neurotransmitters has some stimulatory effects. Norepinephrine, however, is a powerfully stimulating neurotransmitter; it is associated with the 'fight or flight' response, which of course includes an increased heart rate. I believe it may effect epinephrine as well, which is similar to norepinephrine except that it is also a hormone (and a neurotransmitter). This means it has both short and long lasting stimulatory action.

Hope that was helpful!

Answer 2

Does Caffeine Increase Heart Rate

Answer 3

Caffeine Heart Rate

Answer 4

The predominant reason that caffeine raises your heart rate is due to its inhibitory action on an enzyme called phosphodiesterase.

Phosphodiesterases are resposible for the degradation of a molecule called cAMP. This molecule is produced by, among many others, the action of adrenaline and nor-adrenaline on beta-1 adrenoceptors on the myocardial tissue of the heart.

cAMP activates a further enzyme called Protein Kinase A (PKA) which in turn phosphorylates the voltage-gated Ca2+ channels in the cell membranes causing them to staying open for longer. This causes increased force of contraction. The increase in heart rate is caused by modulation of a 'leak'-channel responsible for slow depolarisation of the nodal tissue. This 'funny' current (that really is what it's called) is enhanced meaning that the spontaneous depolarisation of the sinoatrial node is more frequent. Hence your pulse rate goes up.

There's a little more to it but these are the basics.

I case anyone wondered, I'm a pharmacology supervisor at a university.

Answer 5

At low- to moderate-dose caffeine will slow the heart by centrally stimulating the vagus nerve. At higher doses it accelerates the heart and can cause arryhthmias (irregular heart beat); this is the result of multiple mechanisms occuring at the same time.

Aloha

Answer 6

Caffeine is changed in the liver (metabolised) to 3 different chemicals

One of those chemicals (theophylline) stimulates the heart and lungs (we used to give it to asthmatics)

Have a look at the wiki page

Answer 7

This Site Might Help You.

RE:
Why does caffeine increase heart rate?
In laymans terms please!!

Answer 8

caffine stimulates the nervous system ( to work faster)
and the nervous system regulates the beating of the heart.

Answer 9

NetNet is right, that's all you need to know, give her ten points.

Answer 10

because it raises blood pressure.