Kaplan Nursing Entrance Practice Exam 2025 – The All-in-One Guide to Exam Success!

Flexor muscles are primarily located at joints between bones, where they function to decrease the angle between the two bones in a joint when they contract. This action allows for movements such as bending the elbow or knee. For instance, when the biceps muscle contracts, it flexes the elbow joint, bringing the forearm closer to the upper arm.

The other options refer to locations that do not primarily serve the function of flexion. The heart and arteries are primarily associated with cardiovascular functions and smooth muscles, while the brain and spinal cord are part of the central nervous system that coordinates muscle movements rather than containing the flexor muscles themselves. The walls of the stomach contain smooth muscle, which plays a role in digestion rather than in flexing joints. Therefore, the clear association of flexor muscles with joint actions makes the correct response about their primary location at joints between bones.