How do calcium channel blockers (CCBs) function?

Calcium channel blockers (CCBs) specifically function by inhibiting the entry of calcium ions into smooth muscle and myocardial cells. This action leads to arterial vasodilation, meaning the blood vessels widen, which decreases peripheral vascular resistance and can lower blood pressure. By preventing calcium ions from entering these cells, CCBs effectively reduce the force of contraction of the heart and modify the heart rate, but their primary action is on the smooth muscles of the arteries rather than the veins.

Choosing this option highlights the essential role of CCBs in managing hypertension and angina by relaxing arterial walls and improving blood flow. The focus on arterial vasodilation ties into the overall mechanism of cardiovascular health and is a critical aspect of how CCBs are used therapeutically in treating conditions like high blood pressure and certain types of heart disease.