Re: How does temperature of the body influence pulse rate?

The influence that the temperature of the body has on pulse rate is to 
increase it. There is no direct relation but there is an 
indirect relation.

When body temperature is higher for reasons of infection or fever from any 
inflammatory cause, the body also secretes catecholamines to increase 
pulse rate. The result is to increase blood circulation throughout the 
body. This allows more blood supply to the skin vessels where the 
excess heat can be dissipated by the body by the phenomenon of conduction 
and convection.

The thalamus in the brain has a thermostat that tries to regulate body 
temperature at the normal body temperature. When the body temperature is 
higher because of an increase in room temperature or in summer, the 
body tries to cool off by opening small vessels in the skin to an 
increased size to allow more blood flow to skin. This is helped by the 
higher heart rate, since blood flow every minute = stroke volume per beat 
* pulse rate.

But when there is infection in the body the thalamus itself is influenced 
by the production of certain factors by the body's defence cells that 
increase the thermostat setting to make the body generate higher 
temperature. This is done by inducing shivering as ssen in fever and 
chills. By shivering the muscles contract rapidly and generate excess 
heat. This helps the body geneate more heat.

These factors also directly influence heart rate and increase it.
Therefore the relationship as you see between body temp and heart rate is 
indirect.

Hope this helps