Adrenergic receptors

Definition

Adrenergic receptors are a class of G protein-coupled receptors targeted by catecholamines like adrenaline and noradrenaline. They play a crucial role in the sympathetic nervous system by modulating physiological responses such as heart rate, blood pressure, and bronchodilation.

5 Must Know Facts For Your Next Test

1. There are two main types of adrenergic receptors: alpha (α) and beta (β), each with subtypes such as α1, α2, β1, β2, and β3.
2. Alpha-1 receptors are primarily found in vascular smooth muscles and are responsible for vasoconstriction.
3. Beta-1 receptors are predominantly located in the heart and increase heart rate and force of contraction.
4. Beta-2 receptors are found in the lungs and cause bronchodilation when activated.
5. Drugs like beta-blockers (e.g., propranolol) inhibit beta-receptors to manage conditions such as hypertension and anxiety.

Review Questions

• What are the two main types of adrenergic receptors?
• Which adrenergic receptor subtype is most associated with increasing heart rate?
• How do beta-blockers affect adrenergic receptors?

Related terms

Catecholamines:

Neurotransmitters like adrenaline and noradrenaline that activate adrenergic receptors.

Sympathetic Nervous System:

Part of the autonomic nervous system that mediates the 'fight or flight' response.

G Protein-Coupled Receptors:

A large family of cell surface receptors involved in many physiological processes, including adrenergic signaling.