Which function is associated with Beta 2 receptors?

Beta 2 receptors are primarily associated with smooth muscle relaxation and various metabolic processes. They are crucial in mediating bronchodilation, which is the widening of the air passages in the respiratory system, making it easier to breathe. Activation of these receptors leads to the relaxation of bronchial smooth muscle, thereby alleviating conditions such as asthma or bronchospasm.

Additionally, Beta 2 receptors play a role in glycogenolysis, which is the breakdown of glycogen to glucose in the liver, contributing to an increased availability of glucose for energy. This is particularly important in situations of stress or during physical exertion when the body requires rapid energy. The combination of bronchodilation and glycogenolysis is essential for enhancing the body’s ability to respond to demand during stressful situations, such as exercise or acute respiratory distress.

The other responses pertain to actions primarily driven by different adrenergic receptors. For example, vasoconstriction is mainly associated with alpha receptors, increased heart rate is primarily mediated by Beta 1 receptors, and contraction of the bladder neck is more closely linked to alpha receptors as well. Therefore, focusing on the unique actions of Beta 2 receptors clarifies why the correct answer highlights bronchodilation and glycogenolysis.