Smooth muscle of the blood vessels in the brain, skin, gastrointestinal (GI) tract and kidneys.The sympathetic/adrenergic receptors that will be addressed in this article are Alpha1, Alpha2, Beta1 and Beta2 receptors.Īlpha1 receptors are primarily located within the: These receptors are frequently referred to as adrenergic receptors. The physical reactions associated with the sympathetic nervous system are facilitated by the activation of cellular receptors. This is because it helps our body physically “fight” or “flee” from a perceived and/or actual threat. Many people refer to the sympathetic nervous system as the “fight or flight” system. It is also activated during increased physical activity. The sympathetic nervous system rapidly directs the body’s involuntary response to a perceived and/or actual dangerous situation. The primary catecholamine responsible for activating the sympathetic nervous system is a neurotransmitter called norepinephrine. Substances that activate the sympathetic nervous system are frequently referred to as catecholamines. These divisions of the nervous system can be a little confusing refer to the diagram that illustrates these divisions within the nervous system. The autonomic nervous system is then divided into the sympathetic and parasympathetic nervous systems. The autonomic nervous system controls involuntary body responses like the heart, lungs and digestion. Voluntary means we have conscious control over functions such as skeletal muscles, sight and hearing. The somatic nervous system controls body functions that are voluntary. The motor division is divided into the somatic system and autonomic system.

The sensory division can be referred to as the afferent division, and the motor division can be referred to as the efferent division. The peripheral nervous system entails the sensory division that brings information to the brain, and the motor division that sends information from the brain to the body. The central nervous system branches into the peripheral nervous system. Our brain is the foundation of conscious and unconscious thought, as well as how our body interacts with the external environment. The nervous system starts with the central nervous system, which includes the brain and spinal column.

(Photo/Getty Images)īefore delving into the sympathetic and parasympathetic nervous systems, let’s look at the nervous system as a whole. Understanding the sympathetic and parasympathetic nervous systems is especially relevant for paramedics because ALS personnel have access to medications that directly influence these two systems.

The somatic nervous system is