Most organs in the body are under some form of autonomic control and therefore receive nerve fibres from both the SNS and PNS. There are some exceptions to this rule, for example, most blood vessels only receive an SNS supply. In organs where there is dual nerve fibre supply, the two divisions of the ANS almost always have opposing effects. Using the heart as an example, increased activity in the SNS leads to increased cardiac acitivity such as heart rate whilst stimulation of PNS fibres leads to reduced cardiac activity. | Most organs in the body are under some form of autonomic control and therefore receive nerve fibres from both the SNS and PNS. There are some exceptions to this rule, for example, most blood vessels only receive an SNS supply. In organs where there is dual nerve fibre supply, the two divisions of the ANS almost always have opposing effects. Using the heart as an example, increased activity in the SNS leads to increased cardiac acitivity such as heart rate whilst stimulation of PNS fibres leads to reduced cardiac activity. |