Chapter 18, Problem 1O

Summary Introduction

To describe:

The functions of the sympathetic nervous system and the specific effects of adrenergic stimulation.

Concept Introduction:

The central nervous system (CNS) and peripheral nervous system (PNS) are considered as the two important branches of the nervous system. The CNS consists of the spinal cord and brain, whereas the PNS contains autonomic (ANS) and somatic nervous system (SNS). The ANS is further divided into the sympathetic or adrenergic and parasympathetic or cholinergic. It is more important to understand the action of many drugs in these systems. Adrenergic or sympathetic compounds include the substances which are related to the body’s natural substances (endogenous) and synthetic substances (exogenous).

Explanation of Solution

Functions of the sympathetic nervous system:

Adrenergic compounds are involved in the therapeutic effects with the help of their receptors. It stimulates the SNS and it is called as adrenergic agonists. It is also known as sympathomimetic because it mimics the SNS neurotransmitters effects such as norepinephrine, dopamine, and epinephrine. These neurotransmitters are classified in terms of chemical nature as catecholamines. The G-protein coupled adrenergic receptors are targets the catecholamines neurotransmitters such as epinephrine (adrenaline) and norepinephrine (noradrenaline). These adrenergic receptors of the SNS provide the check and balance system to maintain the body homeostasis.

Specific effects of adrenergic stimulation:

It involves the flight or fight responses to acute stress and it is activated due to the unexpected release of hormones. It is also involved in the pupil widening, blood flow diverting from organs to the skeletal muscle.

Conclusion

Thus, the functions and specific effects of adrenergic compounds of the SNS involves the body homeostasis and stimulates the fight or flight responses.