Patient Care Technician (PCT) AAH Practice Exam

What is a critical function of potassium in the human body?

1. Bone strength

2. Muscle contraction and nerve impulse transmission

3. Blood clotting

4. Metabolizing food

The correct answer is: Muscle contraction and nerve impulse transmission

Potassium plays a crucial role in the human body primarily through its involvement in muscle contraction and nerve impulse transmission. It is an essential electrolyte that helps maintain the electrochemical gradient across cell membranes, which is vital for the proper functioning of both muscle and nerve cells. In muscle tissues, potassium facilitates the contraction process by allowing muscle fibers to respond to signals from the nervous system. This involves the movement of potassium ions in and out of muscle cells, leading to changes in electrical potential that trigger contractions. Similarly, in nerves, potassium is essential for generating and propagating action potentials, which are the electrical signals that nerves use to communicate with each other and with muscles. While other functions listed, like bone strength, blood clotting, and metabolizing food, are important to overall health, they are not directly linked to potassium's primary functions in the body. Bone strength is primarily influenced by minerals like calcium and phosphorus, blood clotting involves factors mostly related to calcium and proteins, and a variety of nutrients participate in food metabolism, not just potassium. Therefore, potassium's critical role in muscle function and nerve signal transmission highlights why this option stands out as the correct answer.