Sympathetic Nervous System

The sympathetic nervous system is involved in stimulating the fight-or-flight response of the body. Activating the sympathetic pathway results in physiological effects including the acceleration of heart beat, increase in force of heart contraction, secretion of adrenaline and noradrenaline by the adrenal gland, bronchi relaxation, and the inhibition of peristalsis and gastrointestinal secretions. Neurotransmitters are used to relay neurotransmission in order to bring about these physiological effects. Acetylcholine is a type of neurotransmitter released from the preganglionic nerve which binds to nicotinic receptors in the autonomic ganglion. Noradrenaline is another type of neurotransmitter released from the postganglionic nerve that binds to adrenergic receptors in target tissues of organs to cause physiological responses.