Florida State Paramedic Practice Exam

What physiological effects does beta stimulation produce?

1. Increased heart rate and contractility

2. Vasodilation and bronchodilation

3. Decreased respiratory rate

4. Increased systemic vascular resistance

The correct answer is: Vasodilation and bronchodilation

Beta stimulation primarily refers to the activation of beta-adrenergic receptors by catecholamines, such as epinephrine or norepinephrine. When these receptors are stimulated, particularly the beta-2 receptors, the body experiences significant physiological effects including vasodilation and bronchodilation. Vasodilation occurs as beta-2 receptors, found in vascular smooth muscle, promote the relaxation of blood vessels. This leads to an increase in blood flow to various tissues and organs, especially during times of stress or in response to exercise. Bronchodilation is another crucial effect of beta-2 receptor activation, facilitating the relaxation of bronchial smooth muscle and thus widening the airways. This is particularly beneficial in conditions like asthma or other respiratory disorders, where air passage can be constricted. Understanding the mechanism behind these effects is essential for paramedics, as it allows for the application of beta-agonist medications in emergency situations to relieve respiratory distress and improve circulation. In contrast, the other options do not align with the primary effects of beta stimulation: increased heart rate and contractility are more characteristic of beta-1 stimulation, while a decreased respiratory rate and increased systemic vascular resistance involve different physiological mechanisms that do not result from beta-adrenergic receptor activity.