TCRN Practice Exam 2025 – Complete Prep for Your Test

The ability to flex the fingers and form a fist is primarily innervated at the C8 level of the spinal cord. At this level, the motor neurons that control the muscles responsible for finger flexion, such as the flexor digitorum superficialis and flexor digitorum profundus, are located. These muscles allow the fingers to curl and create a fist, which is essential for grasping and manipulation.

The C8 vertebra is located just above the T1 vertebra, which corresponds to the lower limits of the cervical plexus. The motor function associated with C8 is crucial for hand function. While C6 also contributes to upper limb movement, it is primarily responsible for elbow flexion and wrist extension, rather than fine motor control of the fingers. The thoracic levels, such as T2 and T4, primarily innervate trunk muscles and are not directly involved in the intricate movements of the hands and fingers.

Thus, understanding the anatomical and functional significance of the C8 level is key in recognizing where finger flexion originates and how it plays a vital role in overall hand functionality.