Adrenergic Vs Cholinergic
Within the human body there are lots of receptors that receive messages from certain biologic messengers in order for the specific body systems to function or make an appropriate response. Like the autonomic nervous system (ANS), the division responsible for automatic responses like the beating of the heart and other organ functions involving smooth muscles, this system is further regulated by two specific branches called the adrenergic and cholinergic pathways. Each pathway has its own unique set of receptors and triggers to induce a certain action.
The adrenergic pathway is otherwise known as the SNS or sympathetic nervous system. The other one is the cholinergic pathway which is also regarded as the parasympathetic nervous system (PNS). The main difference between the two is their neurotransmitters. For the cholinergic line, acetylcholine (ACh) is used while the adrenergic line makes use of either norepinephrine or epinephrine (also known as adrenaline); no wonder the adrenergic line came to be named as such because adrenaline is involved.
Because of the action of these neurotransmitters, they will trigger different kinds of effects onto the body. Generally, the PNS or cholinergic induces the ‘digest and rest’ effects while the SNS or adrenergic mimics the effect of the ‘fight or flight response’ as in the case when there is too much excitement. Inducing the digest and rest means that the gastrointestinal (GI) and genitourinary (GU) systems’ effects are increased (excited) while imitating the fight or flight response excites all other system effects except the GI and GU.
The two pathways also have different kinds of receptors that are either excitatory in nature or inhibitory. Nicotinic and muscarinic receptors are part of the cholinergic line while alpha and beta receptors are part of the adrenergic line. These receptors are located in many areas within the body like for the nicotinic receptors, they are mostly found at the skeletal muscles whereas the adrenergic receptors are vastly distributed throughout many parts of the body.
Overall, although both are part of the bigger ANS, the two still differ (in fact their actions oppose each other) because of the following:
1. Adrenergic involves the use of the neurotransmitters epinephrine and norepinehprine while cholinergic involves acetylcholine.
2. Adrenergic is called the sympathetic line (SNS) while cholinergic is called the parasympathetic line (PNS).
3. In general, cholinergic effects or symptoms are like the ‘digest and rest’ while adrenergic effects are congruent to the ‘fight or flight’ response symptoms.
4. Nicotinic and muscarinic receptors are part of the cholinergic line while alpha and beta receptors are involved in the adrenergic line.