Emergency Medical Technician (EMT) Basic Certification 2025 – 400 Free Practice Questions to Pass the Exam

Epinephrine primarily acts as a powerful stimulant that has significant effects on the smooth muscles, particularly in the bronchi and blood vessels. The correct statement highlights that epinephrine relaxes smooth muscles.

This relaxation occurs because epinephrine binds to beta-2 adrenergic receptors located on the smooth muscle cells. When stimulated, these receptors lead to a relaxation response, which is especially critical in the respiratory system, where dilation of the airways (bronchodilation) facilitates easier breathing during conditions such as anaphylaxis or asthma attacks.

This effect is essential for providing immediate relief in emergencies requiring increased airflow and improved oxygenation. Understanding the impact of epinephrine on smooth muscle function is crucial for EMTs, as it enables them to effectively manage allergic reactions and respiratory distress situations by utilizing epinephrine appropriately.