Difference Between Adrenergic and Cholinergic Receptors

Adrenergic and Cholinergic receptors are two different types of transmembrane receptors. Adrenergic and Cholinergic receptors have different effects on the body. Both trigger nerve impulses and respond to neurotransmitters but have different features, properties, and types. The below article covers in detail the difference between adrenergic and cholinergic receptors.

Difference between Adrenergic and Cholinergic Receptors

Differences between Adrenergic and Cholinergic Receptors are given below:

Parameter	Adrenergic Receptors	Cholinergic Receptors
Definition	Adrenergic Receptors are defined as a type of receptors that are present on the surface of cell and gets activated once they bind catecholamine (Hormone secret by adrenal gland).	Cholinergic Receptors are defined as a type of receptors that are present on the surface of cell and gets activated once they bind acetylcholine.
Part of nervous system	Adrenergic Receptors are part of sympathetic nervous system.	Cholinergic Receptors are part of parasympathetic nervous system.
Responding Neurotransmitters	Adrenergic Receptors binds catecholamines namely epinephrine and norepinephrine.	Cholinergic Receptors binds to acetylcholine.
Type of receptors	Adrenergic receptors are G-protein coupled receptors in nature.	Cholinergic receptors are inotropic-ligand-gated and metabotropic receptors in nature.
Effect on heart	Adrenergic Receptors simulates faster activity of heart.	Cholinergic Receptors regulates the activity.
Structure	Adrenergic receptors are glycoproteins.	Cholinergic receptors are integral membrane proteins.
Types	Adrenergic Receptors are further classified as alpha receptors and beta receptors.	Muscarinic Receptors are further classified as nicotinic receptors and muscarinic receptors

Similarities between Adrenergic and Cholinergic Receptors

Similarities between Adrenergic and Cholinergic Receptors are given below:

• Both are autonomic receptors.
• Both Adrenergic and Cholinergic Receptors triggers nerve impulses.
• Adrenergic and Cholinergic Receptors both responds to neurotransmitters.

What are Adrenergic Receptors?

Adrenergic receptors are defined as a type of receptors that binds catecholamines namely epinephrine and norepinephrine that is released from adrenal medulla and sympathetic nervous system. Adrenergic receptors therefore mediates the actions of sympathetic nervous system. Adrenergic receptors are G protein-coupled receptors. Various cardiovascular diseases such as asthma, hypertension and cardiac arrhythmias can be managed either by activating or by blocking the receptors. It is known as a therapeutic approach.

Types of Adrenergic Receptors

Adrenergic Receptors are further classified as given below:

1. Alpha Receptors: All the physiological processes are controlled by alpha receptors. Physiological processes includes pupil dilation, vasoconstriction and intestinal relaxation. Further alpha receptors are classified as Alpha 1 and Alpha 2 receptors.
2. Beta Receptors: Beta receptors are located at cardiac and smooth muscles and are responsible for controlling the tasks such as bronchial and uterine smooth muscles and increase heart rate. Further beta receptors are classified as beta 1, beta 2, and beta 3 receptors.

Cholinergic Receptors

Cholinergic receptors are defined as a type of receptors that are activated by neurotransmitter acetylcholine. These receptors are used in autonomic nervous system. Cholinergic receptors are metabotropic and inotropic in nature. Acetylcholine is released by Cholinergic receptors. Cholinergic receptors responds and binds to acetylcholine and facilitate communication.

Types of Cholinergic Receptors

Cholinergic Receptors are further classified as given below:

1. Nicotinic Receptors: Nicotinic Receptors are simulated by agonist and are inotropic ligand-gated. Nicotinic Receptors functions at the neuromuscular junctions and within the central nervous system. Further Nicotinic Receptors are further divided into N1 and N2 receptors.
2. Muscarinic Receptors: Muscarinic Receptors are simulated by muscarine and are G-protein coupled. Muscarinic Receptors functions in the peripheral and central nervous systems. Muscarinic Receptors are further divided into M1, M2, M3, M4, and M5 Receptors.

FAQs on Adrenergic and Cholinergic Receptors

1. Are Adrenergic and Muscarinic Receptors the Same?

Answer:

No, adrenergic and muscarinic receptors are not the same. adrenergic receptors responds to the binding of norepinephrine whereas muscarinic receptors responds to the binding of ACH.

2. What is Difference between Nicotinic and Muscarinic Receptors?

Answer:

Nicotinic receptors belongs to the group of cholinergic receptors whereas Muscarinic receptors belongs to a group of G-protein coupled cholinergic receptors. Nicotinic receptors responds to nicotine whereas Muscarinic receptors responds to muscarine.

3. What is meant by N1 and N2 Receptors?

Answer:

N1 and N2 receptors both are types of Nicotinic receptors. N1 receptors are located at neuromuscular junctions are are type of muscle receptors whereas N2 receptors located at the synapses between neurons and are type of neuronal receptors.

4. What are Functions of Beta Receptors?

Answer:

Beta receptors are responsible for controlling the tasks such as bronchial and uterine smooth muscles and increase heart rate.