What is a primary action of BETA 2 receptor stimulation by adrenaline?

The primary action of BETA 2 receptor stimulation by adrenaline is to stimulate bronchodilation. When adrenaline binds to BETA 2 adrenergic receptors, primarily located in the smooth muscle of the airways, it causes these muscles to relax. This relaxation widens the air passages (bronchi and bronchioles), making it easier for air to flow in and out of the lungs. This is particularly important for patients experiencing bronchospasm due to conditions such as asthma or chronic obstructive pulmonary disease (COPD).

Understanding the role of BETA 2 receptors is crucial in pharmacology, especially in emergency situations where rapid bronchodilation may be needed to alleviate respiratory distress. The use of adrenaline in this context is effective in reversing bronchospasm and improving airflow.